add consistency rewards

Author: fhenneke

docs/cow-protocol/reference/core/auctions/rewards.md

@@ -5,15 +5,17 @@ sidebar_position: 3
 
 # Solver rewards
 
-The protocol is currently subsidizing the solver competition on all chains it operates on, by rewarding solvers on a weekly basis (currently, every Tuesday) with rewards paid in COW. Solvers are rewarded based on their performance as solvers (i.e., when participating in the standard solver competition) as specified by [CIP-20](https://snapshot.org/#/cow.eth/proposal/0x2d3f9bd1ea72dca84b03e97dda3efc1f4a42a772c54bd2037e8b62e7d09a491f), [CIP-36](https://snapshot.org/#/cow.eth/proposal/0x4e58f9c1208121c0e06282b5541b458bc8c8b76090263e25448848f3194df986), [CIP-38](https://snapshot.org/#/cow.eth/proposal/0xfb81daea9be89f4f1c251d53fd9d1481129b97c6f38caaddc42af7f3ce5a52ec), [CIP-48](https://snapshot.org/#/cow.eth/proposal/0x563ab9a66265ad72c47a8e55f620f927685dd07d4d49f6d1812905c683f05805) [CIP-57](https://snapshot.box/#/s:cow.eth/proposal/0x46d4fea1492207cf400fcb7a01141a7d4c730791d658cc77236941fc9eb7dccb), [CIP-67](https://snapshot.box/#/s:cow.eth/proposal/0xf9ecb08c4738f04c4525373d6b78085d16635f86adacd1b8ea77b2c176c99d32) and [CIP-74](https://snapshot.org/#/s:cow.eth/proposal/0x0c70c8cd92accee872b52614b4fa10e3e3214f45c5b6857f7e88e910607a3c1d). Solver rewards for participating in the price estimation competition and providing quotes that are needed for the gas estimates and limit price computations of market orders are specified in [CIP-27](https://snapshot.org/#/cow.eth/proposal/0x64e061568e86e8d2eec344d4a892e4126172b992cabe59a0b24c51c4c7e6cc33), [CIP-36](https://snapshot.org/#/cow.eth/proposal/0x4e58f9c1208121c0e06282b5541b458bc8c8b76090263e25448848f3194df986), [CIP-57](https://snapshot.box/#/s:cow.eth/proposal/0x46d4fea1492207cf400fcb7a01141a7d4c730791d658cc77236941fc9eb7dccb), and [CIP-72](https://snapshot.box/#/s:cow.eth/proposal/0xc1b1252f0c99126b4e09730022faa31a7bb58073a3dc064c19b74d44164c39a7).
+The protocol is currently subsidizing the solver competition on all chains it operates on, by rewarding solvers on a weekly basis (currently, every Tuesday) with rewards paid in COW. Solvers are rewarded based on their performance as solvers (i.e., when participating in the standard solver competition) as specified by [CIP-20](https://snapshot.org/#/cow.eth/proposal/0x2d3f9bd1ea72dca84b03e97dda3efc1f4a42a772c54bd2037e8b62e7d09a491f), [CIP-36](https://snapshot.org/#/cow.eth/proposal/0x4e58f9c1208121c0e06282b5541b458bc8c8b76090263e25448848f3194df986), [CIP-38](https://snapshot.org/#/cow.eth/proposal/0xfb81daea9be89f4f1c251d53fd9d1481129b97c6f38caaddc42af7f3ce5a52ec), [CIP-48](https://snapshot.org/#/cow.eth/proposal/0x563ab9a66265ad72c47a8e55f620f927685dd07d4d49f6d1812905c683f05805) [CIP-57](https://snapshot.box/#/s:cow.eth/proposal/0x46d4fea1492207cf400fcb7a01141a7d4c730791d658cc77236941fc9eb7dccb), [CIP-67](https://snapshot.box/#/s:cow.eth/proposal/0xf9ecb08c4738f04c4525373d6b78085d16635f86adacd1b8ea77b2c176c99d32), [CIP-74](https://snapshot.org/#/s:cow.eth/proposal/0x0c70c8cd92accee872b52614b4fa10e3e3214f45c5b6857f7e88e910607a3c1d), and [CIP-XX](<snapshot-link>). Solver rewards for participating in the price estimation competition and providing quotes that are needed for the gas estimates and limit price computations of market orders are specified in [CIP-27](https://snapshot.org/#/cow.eth/proposal/0x64e061568e86e8d2eec344d4a892e4126172b992cabe59a0b24c51c4c7e6cc33), [CIP-36](https://snapshot.org/#/cow.eth/proposal/0x4e58f9c1208121c0e06282b5541b458bc8c8b76090263e25448848f3194df986), [CIP-57](https://snapshot.box/#/s:cow.eth/proposal/0x46d4fea1492207cf400fcb7a01141a7d4c730791d658cc77236941fc9eb7dccb), and [CIP-72](https://snapshot.box/#/s:cow.eth/proposal/0xc1b1252f0c99126b4e09730022faa31a7bb58073a3dc064c19b74d44164c39a7).
 
 :::note
 
 For the interested reader, the main source of truth for the weekly payments to solvers is this [Dune dashboard](https://dune.com/cowprotocol/cow-solver-rewards). The dashboard is populated with data aggregated by scripts within the [solver-rewards](https://github.com/cowprotocol/solver-rewards) repository.
 
 :::
 
-## Solver competition rewards (CIPs 20, 36, 38, 48, 57, 67, 74)
+## Solver competition rewards (CIPs 20, 36, 38, 48, 57, 67, 74, XX)
+
+### Performance rewards
 
 Solver rewards are computed using a mechanism akin to a Vickrey–Clarke–Groves mechanism (a generalization of a second-price auction to combinatorial auctions). First, each solver proposes multiple solutions. Each solution contains a price vector and a list of trades to execute, which can be used to compute the solution's score. The protocol then selects the winning solutions (and winning solvers) using a fair combinatorial auction, which first filters out the solutions deemed unfair and then selects the combination of fair solutions that maximizes the total score of the auction (see [here](competition-rules#off-chain-protocol) for more details).
 
@@ -23,21 +25,21 @@ From the protocol's perspective, a solution as executed on chain must equal the
 
 :::
 
-The payment to the winning solver $$i$$ is
+The performance reward to the winning solver $$i$$ is
 
 $$
-\textrm{payment}_i = \textrm{cap}(\textrm{totalScore} - \textrm{referenceScore}_i-\textrm{missingScore}_i).
+\textrm{performanceReward}_i = \textrm{cap}(\textrm{totalScore} - \textrm{referenceScore}_i-\textrm{missingScore}_i).
 $$
 
 Here $$\textrm{totalScore}$$ is the sum of the scores of all winning solutions in the auction and $$\textrm{missingScore}_i$$ is the sum of the scores of solver $$i$$'s winning solutions that reverted. Finally, $$\textrm{referenceScore}_i$$ is the total score of a counterfactual auction in which all bids from solver $$i$$ are removed from the set of bids that survive the fairness filtering.
 
 :::note
 
-The payment calculation can result in a negative figure, in which case the solver is required to pay the protocol.
+The performance reward calculation can result in a negative figure, in which case the solver is required to pay the protocol.
 
 :::
 
-The payment is capped from above and below using the function $$\textrm{cap}(x) = \max(-c_l, \min(c_u, x))$$, where $$c_u$$ is the protocol fee (excluding partner fees) that the protocol earned from the trades in all solutions supplied by the solver in that auction and $$c_l$$ is chain-specific, determined by the following values:
+The performance reward is capped from above and below using the function $$\textrm{cap}(x) = \max(-c_l, \min(c_u, x))$$, where $$c_u$$ is 50% of the protocol fee (excluding partner fees) that the protocol earned from the trades in all solutions supplied by the solver in that auction and $$c_l$$ is chain-specific, determined by the following values:
 
 - Ethereum mainnet, Arbitrum, and Base chain: $$0.010 \;\textrm{ETH}$$
 - Gnosis Chain: $$10 \;\textrm{xDAI}$$
@@ -56,6 +58,24 @@ There is no guarantee that the per-auction rewards are greater than the costs of
 
 :::
 
+### Consistency rewards
+
+In each auction, solver $$i$$'s contribution to the consistency budget is
+
+$$
+\frac{1}{2} \cdot \textrm{protocolFee}_i - \max(0, \textrm{performanceReward}_i),
+$$
+
+where $$\textrm{protocolFee}_i$$ is the protocol fee (excluding partner fees) earned from the trades in all solutions supplied by solver $$i$$. When the performance reward is a penalty (i.e., negative), the full $$\frac{1}{2} \cdot \textrm{protocolFee}_i$$ is contributed to the consistency budget. The total consistency budget for an accounting period is the sum of these contributions across all solvers and auctions.
+
+The consistency budget is distributed at the end of each accounting period according to a consistency metric. The core team has a mandate to adapt this metric over time; every change will be announced in advance on the [CoW Protocol forum](https://forum.cow.fi).
+
+**Current metric: order count.** Each solver's share of the consistency budget is proportional to the number of executed orders for which it submitted a solution:
+
+$$
+\textrm{consistencyReward}_i = \textrm{consistencyBudget} \times \frac{\textrm{orderCount}_i}{\sum_j \textrm{orderCount}_j}.
+$$
+
 ### Buffer accounting
 
 It is possible that the state of the external liquidity sources used as part of a solution changes between the bidding stage and the execution stage. We say that there is negative slippage when the solver's execution generates less than the expected amount, and positive slippage otherwise. In case of negative slippage the solver can utilize the buffers available in the settlement contract, while a solver can accumulate positive slippage in the settlement contract. Every week, the protocol computes a "net" slippage and either pays a solver (when it is positive) or requests a payment from a solver (when it is negative). For more information, see the [accounting section](/cow-protocol/reference/core/auctions/accounting).
@@ -72,7 +92,9 @@ With respect to optimal bidding, note that the protocol rewards allow a solver t
 
 The presence of the cap on rewards $$c_u$$, however, makes the problem more complex as it introduces a "first-price auction" logic: if the difference between the best and second-best solution is very large, then the winning solver wins more when it underreports its score. The filtering step of the fair combinatorial auction also makes this problem more complex, because there are some edge cases in which by reducing the score of a solution, solver $i$ can benefit by making the filtering steps less stringent for its opponents (see [here](https://forum.cow.fi/t/combinatorial-auctions-from-theory-to-practice-via-some-more-theory-about-rewards/2877) for a discussion). However, determining the optimal amount of underreporting is very complex and requires each solver to make strong assumptions regarding the performance of competing solvers.
 
-To summarize, truthfully revealing the (cost-adjusted) score that a solver can generate for each submitted solution is optimal if the cap is not binding, and misreporting does not affect $$\textrm{referenceScore}_i$$. It is not necessarily optimal in uncompetitive auctions when the difference between the best and second-best solution may be large, and in some edge cases in which a solver may benefit from making the filtering step less stringent. However, in these cases, deriving the optimal strategy is a very complex problem. We conclude by noting that most CoW Protocol batches are very competitive - at the time of writing (November 2025) the cap on rewards is binding only in about 9% of auctions - and that a solver benefits by making the filtering steps less stringent for its opponents only in sporadic cases.
+To summarize, truthfully revealing the (cost-adjusted) score that a solver can generate for each submitted solution is optimal if the cap is not binding, and misreporting does not affect $$\textrm{referenceScore}_i$$. It is not necessarily optimal in uncompetitive auctions when the difference between the best and second-best solution may be large, and in some edge cases in which a solver may benefit from making the filtering step less stringent. However, in these cases, deriving the optimal strategy is a very complex problem.
+
+Consistency rewards introduce an additional strategic dimension: since the order-count metric rewards solvers for submitting solutions to auctions in which orders are ultimately executed, solvers have an incentive to participate broadly across auctions, even in cases where they do not expect to win the performance reward.
 
 ## Price estimation competition rewards (CIPs 27, 36, 57, 72)