Appellants, creditors holding partially secured claims (“appellants” or “secured lenders”) against property of the estate of the chapter 11 debtor,1 Erin Food Services, Inc. (“debtor” or “Erin”), challenge a bankruptcy court order setting aside, as voidable preferences, three installment interest payments Erin made to appellants, within one year of the chapter 11 petition, on an antecedent debt guaranteed by an Erin “insider.” Appellants argue that (1) Bankruptcy Code § 550(a) does not permit direct recovery from the non-insider transferees unless the transfers were made within the conventional ninety-day preference period; (2) even assuming the transfers were directly recoverable from the non-insiders under section 550, the trustee did not establish that the insider-guarantor derived a cognizable “benefit” from the transfers, a prerequisite to their avoidance under Bankruptcy Code §§ 547(b)(1), (b)(4), and (b)(5); and (3) as transfers in the “ordinary course of business,” the installment interests payments are not subject to avoidance under Bankruptcy Code § 547(c)(2).

I

BACKGROUND

In 1971, David W. Murray (the “insider”) acquired exclusive franchises from Burger King Corporation to own and operate restaurants in parts of New Hampshire and Massachusetts. Murray established Erin to operate the restaurants. By 1987, Erin was operating more than twenty Burger King restaurants on real estate either leased or subleased from Murray, Erin’s sole shareholder. Murray retained title to twenty-two parcels of real estate.

In order to fund an expansion, Erin negotiated a long-term refinancing arrangement with the secured lenders in July 1987. As primary obligor, Erin borrowed $45 million, most of which was disbursed by the secured lenders directly to Erin’s existing *795creditors and mortgage lenders. As part of the same refinancing, the secured lenders agreed to provide Erin with a $25 million dollar secured revolving credit account (“RCA”), from which Erin could withdraw funds for future franchise expansion, site acquisition, and working^ capital. Both loans, totalling $70 million, were secured by an Adjusted Collateral Pool (“ACP”), which included Erin’s “cash-flow” assets, such as its equipment and franchise agreements. In addition, the secured lenders obtained Murray’s personal non-recourse guaranty on both Erin loan obligations. The guaranty was secured by liens on the twenty-two parcels of real estate owned by Murray.2

During the eleven-month period between the loan and the July 5, 1988, installment interest payment, Erin withdrew $3,249,990 from the RCA, including $2,808,290 with which to make the three installment interest payments to the secured lenders as they became due on April 1, July 1, and July 5, 1988. Erin was rendered insolvent. In re Erin Food Servs., Inc., 117 B.R. 21, 29 (Bankr.D.Mass. 1990).3 Within a year of the first installment interest payment to the secured lenders, an involuntary chapter 11 petition was filed against Erin and an operating trustee was appointed. At the date of the petition, the real estate securing Murray’s personal guaranty had an approximate value of $19.35 million and Erin’s total indebtedness to the secured lenders approximated $61.7 million.

The trustee initiated an adversary proceeding against the secured lenders to recover the three installment interest payments as voidable preferences. See Bankruptcy Code § 547(b), 11 U.S.C. § 547(b). The bankruptcy court concluded that $2,089,059 was recoverable directly from the secured lenders as voidable preferential transfers.4 The secured lenders appeal from the district court judgment affirming the bankruptcy court order. 140 B.R. 14.

II

DISCUSSION

A. Trilateral Preferences: Transfers to Non-insiders During Extended One-Year Preference Period

The soundness of the avoidance theory adopted by the bankruptcy court ultimately turns on the proper interpretation of Bankruptcy Code §§ 547(b) and 550(a), governing the avoidability and recovery of preferential transfers. Section 547(b) permits the trustee in bankruptcy to avoid certain pre-petition transfers of property of the debtor on account of an antecedent debt as a consequence of which a creditor receives more than it would have received in a chap*796ter 7 liquidation proceeding.5 Section 547(b)(4), however, distinguishes between (1) preferential transfers to or for the benefit of an “insider,” typically a “director,” “officer,” or other “person in control of the debtor,” Bankruptcy Code § 101(30), 11 U.S.C. § 101(30), which are avoidable if made within one year of the date of the petition; and (2) transfers to or for the benefit of non-insiders, which are not avoidable unless made within ninety days. Bankruptcy Code § 547(b)(4), 11 U.S.C. § 547(b)(4). The one-year preference period is designed to inhibit insiders — entities normally privy to inside financial information long before it becomes available to arm’s-length creditors — from influencing the insolvent debtor to deplete its remaining assets for the insider’s benefit, to the detriment of non-insider creditors. The secured lenders concede that Murray is an Erin “insider.”

The bankruptcy court correctly found that the secured lenders held a secured claim of $53,842,400, a $2,089,059 million unsecured claim, and an equitably subordinated claim in the amount of $5,827,541.6 On the other hand, Murray, personal guarantor of the Erin debt to the secured lenders, held a contingent unsecured claim against Erin equal to the value of the collateral Murray pledged to secure his non-recourse personal guaranty. The greatly broadened definition of “claim” under Bankruptcy Code § 101(4), as any “right to payment, whether or not such right is reduced to judgment, liquidated, unliquidated, ... legal, equitable, secured, or unsecured,” 11 U.S.C. § 101(4), unquestionably encompasses contingent claims for contribution, reimbursement or indemnification. See In re C-L Cartage Co., 899 F.2d 1490, 1493 (6th Cir. 1990); see also In re Hemingway Transport, Inc., 954 F.2d 1, 8 (1st Cir. 1992). A “creditor” is an “entity that has a claim against the debtor that arose at the time of or before the order for relief....” Bankruptcy Code § 101(9), 11 U.S.C. § 101(9). Thus, both Murray, the insider, and the non-insider secured lenders, independently qualify as Erin “creditors” on the same obligation.

Nevertheless, since Murray alone qualifies as an “insider,” only a transfer which conferred cognizable “benefit” on Murray, see Bankruptcy Code § 547(b)(1) (“to or for the benefit of a creditor”) (emphasis added), would trigger the one-year preference period under Bankruptcy Code § 547(b)(4) (“creditor ... was an insider”).7 The insider guaranty by Murray ostensibly provided the last link needed to convert these install*797ment interest payments into trilateral preferences. There can be no question that an insider-guarantor derives measurable economic benefit from a payment on the guaranteed debt, to the extent the insider’s contingent liability on the personal guaranty is reduced. The trustee accordingly contends that the installment interest payments Erin made to the secured lenders conferred a simultaneous “benefit” upon Murray as well as the secured lenders. Finally, the trustee contends that, as “creditor” Murray received benefit from the installment interest payments made by Erin, the one-year preference period applies.

Once the transfer is determined avoidable under section 547(b), the trustee looks to the greatly broadened recovery powers conferred by section 550(a).8 Thus, a trustee may elect to recover the property (or value) involved in an avoided transfer either from the “entity for whose benefit such transfer was made” (i.e., Murray) or from the “initial transferee of such transfer” (i.e., the secured lenders). Since section 550(a) makes no distinction similar to that found in section 547(b) between the treatment of insiders and non-insiders, the bankruptcy court ordered the secured lenders to remit the installment interest payments to the trustee even though the secured lenders were not “insiders” to whom a prepetition transfer would trigger the one-year preference period under section 547(b)(4).

The bankruptcy court relied on the landmark decision in Levit v. Ingersoll Rand Fin. Corp. (In re V.N. Deprizio Constr. Co.), 874 F.2d 1186 (7th Cir. 1989) [hereinafter “Deprizio ”], which is premised on the presumed “unfair” advantage that non-insider creditors, holding personal guaranties from insider creditors, may have over arm’s-length creditors. See id. at 1195 (absent the one-year preference period for outside creditors with “insider” personal guaranties, nervous, “non-guaranteed” creditors might “grab assets themselves ... or precipitate bankruptcy at the smallest sign of trouble, hoping to ‘catch’ inside preferences before it is too late”); see also In re Kroh Bros. Dev. Co., 115 B.R. 1011, 1015 (Bankr.W.D.Mo. 1990).

B. The Scope of the Deprizio Rule

The proper interpretation and accommodation of sections 547(b) and 550(a) presents an issue of first impression in the First Circuit. The Deprizio rule represents a radical departure from pre-Bankruptcy Code practice.9 Under Dean v. Davis, 242 U.S. 438, 443, 37 S.Ct. 130, 131, 61 L.Ed. 419 (1917), and Bankruptcy Act § 60, 11 U.S.C. § 96, the trustee in bankruptcy could recover a preferential transfer only from an entity in whose hands it represented a “preference” within the terms of the preference avoidance section itself. See supra note 7. The Deprizio rule has been adopted by the three courts of appeals which have addressed the trilateral preference problem,10 even though many lower *798courts have rejected Deprizio on a variety of grounds.

Discerning no indication in the legislative history of Bankruptcy Code 550(a), 11 U.S.C. § 550(a), that Congress ever considered the trilateral preference problem, some bankruptcy courts have relied on their “equitable powers” to override whatever “plain” statutory language might be perceived to require the Deprizio approach, so as not to penalize an “innocent” non-insider “for its prudence in seeking a guarantor of the debt.” In re R.A. Beck Builder, Inc., 34 B.R. 888, 894 (Bankr.W.D.Pa. 1983); see also In re Arundel Hous. Components, Inc., 126 B.R. 216 (Bankr.D.Md. 1991); In re Aereo Metals, Inc., 60 B.R. 77 (Bankr.N.D.Tex. 1985); In re Cove Patio Corp., 19 B.R. 843 (Bankr.S.D.Fla. 1982). Other courts have adopted a theoretical “two-transfer” analysis, which treats a single transfer within the one-year preference period as both a direct transfer to the non-insider creditor and an indirect “transfer” benefitting the insider creditor, thereby permitting the trustee to recover only the latter “transfer” from the preferred insider. See, e.g., In re Mercon Indus., Inc., 37 B.R. 549 (Bankr.E.D.Pa. 1984) (“[T]he Code dictates that there are two transfers rather than one, [and] liability of the guarantors under § 547(b) need not be predicated on a finding of an avoidable transfer to [the non-insider creditor], since a finding of liability on one transfer is independent of the other, rather than derivative.”). Other courts hold that sections 550(a) and 547(b) are better harmonized by subordinating the more general statutory language in section 550(a) to the specific language in section 547(b)(4), prescribing separate preference periods for application to insider and non-insider transfers. See In re Midwestern Cos., 102 B.R. 169 (W.D.Mo. 1989) (Deprizio interpretation effectively obliterates specific distinction in § 547(b)(4) between insider and non-insider creditors);11 see also In re Performance Communications, Inc., 126 B.R. 473 (Bankr.W.D.Pa. 1991). Finally, some other courts reject the Deprizio rule simply on policy grounds by reason of its presumed detrimental effects on commercial lending markets. See In re Rubin Bros. Footwear, Inc., 119 B.R. 416, 425 (S.D.N.Y. 1990) {Deprizio rule “would likely impede the availability of credit to ailing businesses.”).

We need not revisit the underlying issue addressed in Deprizio. First, the difficulties hampering each attempt (including De-prizio ) to unravel the riddle of ill-expressed (or unexpressed) congressional intent are well recorded.12 Second, a definitive congressional resolution to the riddle may be in the offing. See S.1985, 102d Cong., 2d Sess. (1992); see also 138 Cong. Rec. S8241 (“[S]ection [204] seeks to overturn the Deprizio line of opinions_”). *799Finally, and more importantly, the particular circumstances before us afford a more conspicuous basis for decision. Therefore, for present purposes, we assume, without deciding, that Deprizio correctly interprets the legislative directives to be applied to the present claim.

Deprizio did not propound a per se rule enabling the recovery of every temporally vulnerable transfer to a non-insider merely because its claim against the debtor is guaranteed by an insider. See Deprizio, 874 F.2d at 1199 (“§ 547(b)(5) and (c) ... [will] exclude from recovery the bulk of ordinary commercial payments.”) Even under Deprizio, the trustee is not entitled to recover without first establishing, by a preponderance of the evidence, all five elements of a preference as set forth in section 547(b). Bankruptcy Code § 547(g), 11 U.S.C. § 547(g); In re T.B. Westex Foods, Inc., 950 F.2d 1187, 1190 (5th Cir. 1992). In the present case, therefore, the one-year preference period under section 547(b)(4) will not apply unless the trustee can demonstrate that it was Murray, the only “creditor” who was also an “insider,” see § 547(b)(5) (“that enables such creditor”) (emphasis added), who received not only a cognizable “benefit” from the challenged transfers, see 11 U.S.C. § 547(b)(1), but a greater benefit than would have been received in the event Erin had been liquidated under chapter 7, see 11 U.S.C. § 547(b)(5). See In re C-L Cartage, 899 F.2d at 1493.

The trustee contends that Murray received at least two types of “benefit” from Erin’s interest payments to the secured lenders: (1) whatever unquantifiable benefit Murray realized as a consequence of the resultant one-year delay in the commencement of involuntary chapter 11 proceedings against Erin, which in turn (i) insulated Murray from more immediate foreclosure proceedings against the collateral pledged to support his non-recourse personal guaranty of Erin’s debt to the secured lenders, (ii) preserved his equity in the pledged collateral, and (iii) “bought” valuable operating time in which Erin could try to work its way out of insolvency, and (2) the quantifiable dollar-for-dollar reduction in .his contingent liability to the secured lenders on the non-recourse personal guaranty.

1. Delay in Commencement of the Erin Involuntary Chapter 11 Proceedings

The determination as to what constitutes a cognizable “benefit” within the meaning of Bankruptcy Code § 547(b)(1) is an issue of statutory interpretation, a question of law subject to de novo review. See In re LaRoche, 969 F.2d 1299, 1301 (1st Cir. 1992) (standard of review in bankruptcy cases); In re Crouthamel Potatp Chip Co., 786 F.2d 141, 144 (3d Cir. 1986) (interpretation of terms in Bankruptcy Code is a question of law subject to plenary appellate review). The bankruptcy court apparently accepted the trustee’s position, as it found that Murray derived unquantified “benefit” from the challenged transfers. Erin Food, 117 B.R. at 29 (“[T]he larger obligation of Murray’s Burger King property has to protect the greater, his likelihood of ultimate liquidation or smaller, his recovery of those assets.”). Nevertheless, we are unpersuaded that whatever unquantifiable “insider” advantage may attend a deferral of bankruptcy proceedings represents a cognizable “benefit” for section 547(b)(1) purposes. No matter the merits of the Deprizio rule, there is no hint in the Code, its legislative history, or in pre-Code law that Congress ever considered, let alone intended, that the term “benefit” might encompass such incorporeal ephemera as “buying time.”13

*800The trustee relies on alleged ambiguity in the language of section 547(b) — in particular, the terms “benefit” and “received more” — to support the contention that some intangible benefit, even if unrelated to actual variations in the dollar amount of the insider creditor’s hypothetical chapter 7 “claim,” may suffice to establish a voidable preference. When confronted with an alleged ambiguity in the Bankruptcy Code, courts may consult pre-Code law for appropriate guidance, based on the presumption that Congress did not intend to effect substantive changes in prior bankruptcy law unless its intent is clearly expressed in the Code. See Midlantic Nat’l Bank v. New Jersey Dept. of Envtl. Protection, 474 U.S. 494, 501, 106 S.Ct. 755, 759, 88 L.Ed.2d 859 (1986). Section 60(a)(1) of the Bankruptcy Act provided, in pertinent part:

A preference is a transfer, as defined in this title, of any property of a debtor to or for the benefit of a creditor for or on account of an antecedent debt ... the effect of which transfer will be to enable such creditor to obtain a greater percentage of his debt than some other creditor of the same class.

(Emphasis added.) Thus, the immediate forerunner of the term “received more” is found in the definitive phrase “greater percentage of his \i.e., the creditor’s] debt.” Under the Bankruptcy Act, there was a direct pro tanto correlation between the amount of “benefit” and the dollar amount of the reduction in the creditor’s claim. See, e.g., Kapela v. Newman, 649 F.2d 887, 890 (1st Cir. 1981) (“greater percentage” test refers to insider guarantors’ “ ‘contingent debt ’ for repayment of their payment on the guaranty,” and noting that the insiders were “benefitted as guarantors by a reduction in the amount due on the [debtor’s] Loan”) (emphasis added). Assuming arguendo that the language of Bankruptcy Code § 547(b) is more ambiguous than Bankruptcy Act § 60, the legislative history of the Bankruptcy Code makes clear that Congress never intended to alter the focus of the preference avoidance section in any respect relevant to the present discussion. See, e.g., H.R.Rep. No. 595, 95th Cong., 1st Sess. 372 (1978), reprinted in 1978 U.S.C.C.A.N. 5787, 5873 (under both Bankruptcy Act § 60 and Bankruptcy Code § 547(b), “the court must focus on ... the amount that will be received by the members of the class of which the preferee is a member,” and “the transfer must enable the creditor to whom or for whose benefit it was made to receive a greater percentage of his claim than he would have received under the distributive provisions of the bankruptcy code.”) (emphasis added); see generally 3 James W. Moore, Collier on Bankruptcy ¶ 60.34 at 902 (14th ed. 1977).

Construed in unison, subsections 547(b)(1), (2), (4), and (5), harmoniously accommodate the identical direct correlation between the creditor “benefit” addressed in subsection 547(b)(1) and the informing language in subsection 547(b)(5) which requires the trustee to demonstrate that the challenged transfer enabled the creditor to “receive more” than he would have received on the same claim in a chapter 7 liquidation case. Under subsections 547(b)(1) and (2), the challenged transfer must have been made for the benefit of the “creditor” “on account of an antecedent debt”; and for present purposes the relevant antecedent “debt” identified in subsection 547(b)(5)(C) would be the claim on which Murray would have been entitled to “receive[ ] payment” from Erin’s chapter 7 estate.

The equation could not be more clear. Unless the creditor for whose “benefit” the transfer was made, see 11 U.S.C. § 547(b)(1), realized some quantifiable monetary advantage from the debtor’s transfer, there would be no practicable *801method for determining whether “such creditor ... receive[d] more than such creditor would receive” in the event of a chapter 7 liquidation, 11 U.S.C. § 547(b)(5). Thus, interpreting all its parts harmoniously, as we must, see, e.g., McCuin v. Secretary of Health and Human Servs., 817 F.2d 161, 168 (1st Cir. 1987), we believe section 547(b) plainly mandates that the “benefit” inquiry under section 547(b)(1) be confined, as in Deprizio and every other trilateral preference case, see supra notes 10-12 and accompanying text (and cases cited therein), to transfers of the debtor’s property which are shown to have resulted in a quantifiable monetary reduction in the insider-creditor’s contingent claim against the debtor’s chapter 7 estate to the detriment of other creditors of the same class.14

2. Reduction in Contingent Liability on Non-recourse Personal Guaranty

We return to the question with which we began: whether the interest payments Erin made to the secured lenders reduced the amount of Murray's contingent claim against Erin. Whether a creditor has received a quantifiable “benefit” from the challenged transfer for purposes of section 547(b), and whether that “benefit” exceeds the amount receivable in a hypothetical liquidation proceeding, are questions of fact. See In re V.N. Deprizio Constr. Co., 86 B.R. 545, 553 (N.D.Ill. 1988), rev’d on other grounds sub nom., Levit v. Ingersoll Rand Fin. Corp., 874 F.2d 1186 (7th Cir. 1989); see also Max Sugarman Funeral Home v. A.D.B. Investors, 926 F.2d 1248, 1255 (1st Cir. 1991) (findings pf fact by the bankruptcy court will be disturbed only if clearly erroneous). While we may affirm the bankruptcy court ruling on any ground supported by the record, see Hemingway, 954 F.2d at 9, the trustee must point to competent evidence from which the bankruptcy court could have adduced the essential findings of fact underlying its ruling.

Since the non-insider creditor in a trilateral preference receives direct payment on its antecedent debt, the insider guarantor will realize a corresponding dollar-for-dollar reduction in the amount of his contingent liability on the guarantee, see, e.g., Kapela v. Newman, 649 F.2d at 890 n. 3, except in cases like the present where the insider has guaranteed less than the full amount of the primary debt, or where the primary debt is fully secured by property of the debtor at the time of the challenged transfer.15

*802Although the secured lenders realized the full “benefit” of the $2.8 million received in interest payments, there was no reduction whatever in Murray’s liability on the non-recourse guaranty. The evidence at trial established the value of the collateral securing Murray’s non-recourse guaranty at $19.35 million. Since the personal guaranty was “without recourse” at the time the interest payments were made,16 Murray had no contingent liability to the secured lenders on Erin’s $61.7 million debt, beyond the $19.35 million in collateral Murray pledged to secure the guaranty.17 Unless the net balance on Erin’s $61,741,-000 debt to the secured lenders fell below $19.35 million as a result of the challenged transfers, or the value of the ACP exceeded $42.39 million at the time of the transfers, no cognizable “benefit” could accrue to Murray. The former proposition cannot be established solely on the basis of a loan payment of $2.08 million, and the trustee did not assert or establish the latter proposition. Accordingly, Murray’s exposure on the entire $19.35 million in collateral securing the guaranty remained constant throughout, unaffected by the challenged loan payments to the secured lenders. Cf Kroh Bros., 115 B.R. at 1016 (where the non-insider creditor “agreed to look exclusively to the shopping center property in the event of default,” the “insider” non-recourse guarantor was not even a “creditor” of the debtor).18

As the trustee did not show that the challenged transfers from Erin to the secured lenders resulted in a cognizable “benefit” to Murray, the trustee failed, a fortiori, to establish that the challenged transfers enabled Murray to receive more than he would receive on his claim in a case under chapter 7. See Bankruptcy Code § 547(b)(5), 11 U.S.C. § 547(b)(5). The bankruptcy court is required to compare the monetary benefit the creditor in fact received from the alleged preferential *803transfer with the projected amount of any distribution to the same creditor in the event there were an order for relief under chapter 7 and the preferential transfer had never occurred. See, e.g., In re Tenna Corp., 801 F.2d 819, 822 (6th Cir. 1986) (hypothetical chapter 7 distribution constructed as of date of petition, not the date of the proceeding to avoid the transfer); In re Buyer’s Club Markets, Inc., 123 B.R. 895, 896-97 (Bankr.D.Colo. 1991) (same); cf. Palmer Clay Prods. Co. v. Brown, 297 U.S. 227, 229, 56 S.Ct. 450, 450-51, 80 L.Ed. 655 (1936) (pre-Code rule the same). Even if the defendant-creditor does derive a cognizable “benefit,” the transfer is avoidable only if it “ ‘diminish[ed] the fund to which creditors of the same class [as the defendant-creditor] can legally resort for the payment of their debts.’ ” Kapela, 649 F.2d at 892 (emphasis added) (citation omitted). Transfers to a fully-secured creditor, for example, are not avoidable as preferences, since the secured claim would be satisfied in full in a chapter 7 liquidation. See Deprizio, 874 F.2d at 1199-1200. Except in the unusual circumstance where a debtor’s estate is adequate to provide payment in full on all unsecured claims, unsecured creditors who receive payment during the applicable preference period will rarely be spared by section 547(b)(5). See, e.g., In re Cavalier Homes of Georgia, Inc., 102 B.R. 878, 888 (Bankr.M.D.Ga. 1989).

Thus, the subsection 547(b)(5) analysis adopted by the bankruptcy court was flawed at the outset as a consequence of its mistaken interpretation of subsection 547(b)(1) (“to or for the benefit of a creditor”) (emphasis added). See supra notes 13-14 and accompanying text. If Erin had not made the three interest payments, Murray would have held a contingent unsecured claim against the debtor estate in the amount of $19.35 million; immediately after the challenged transfers, Murray held a contingent unsecured claim in the same amount.19 As the trustee failed to sustain *804his burden of proof under subsection 547(b), we do not reach the secured lenders’ challenge to the disallowance of their “ordinary course of business” defense under Bankruptcy Code § 547(c)(2).

The district court judgment affirming the decision of the bankruptcy court is reversed, costs to appellants.