diff --git a/.github/workflows/strength-batch.yml b/.github/workflows/strength-batch.yml
index 9a4c65c3..c1f03720 100644
--- a/.github/workflows/strength-batch.yml
+++ b/.github/workflows/strength-batch.yml
@@ -76,6 +76,12 @@ on:
         description: Passed to fastchess as tc.
         type: string
         required: true
+      candidate_time_control:
+        description: >
+          A clock for the candidate alone, which makes this a time odds match.
+          Empty gives both sides time_control.
+        type: string
+        default: ""
       sprt:
         description: Judge a sequential test over the pooled pairs.
         type: boolean
@@ -144,6 +150,7 @@ jobs:
       BATCH: ${{ inputs.batch }}
       BATCHES: ${{ inputs.batches }}
       TIME_CONTROL: ${{ inputs.time_control }}
+      CANDIDATE_TIME_CONTROL: ${{ inputs.candidate_time_control }}
       BOOK: ${{ inputs.book }}
       SPRT: ${{ inputs.sprt }}
       ELO0: ${{ inputs.elo0 }}
@@ -184,7 +191,7 @@ jobs:
           scripts/build_at.sh "$CANDIDATE_SHA" tools/new
           scripts/build_at.sh "$BASELINE_SHA" tools/old
 
-      - uses: aywrite/mache/actions/play-shard@e3a59ce295c9dfabb62ddb077e88606d022cc55d # v0.7.1
+      - uses: aywrite/mache/actions/play-shard@10f17c5120bb58dfacf2304532bbc63aef86fabe # unreleased, aywrite/mache#35
         id: play
         with:
           candidate: ${{ inputs.candidate_name }}
@@ -200,6 +207,7 @@ jobs:
           batch: ${{ inputs.batch }}
           batches: ${{ inputs.batches }}
           time_control: ${{ inputs.time_control }}
+          candidate_time_control: ${{ inputs.candidate_time_control }}
           hash_mb: ${{ inputs.hash_mb }}
           concurrency: ${{ inputs.concurrency }}
           startup_ms: ${{ inputs.startup_ms }}
@@ -241,7 +249,11 @@ jobs:
             echo "shard: ${SHARD}"
             echo "start: ${START:-not chosen, the shard did not get that far}"
             echo "pairs: ${PAIRS}"
-            echo "time_control: ${TIME_CONTROL}"
+            if [ -n "$CANDIDATE_TIME_CONTROL" ]; then
+              echo "time_control: ${TIME_CONTROL} for the baseline, ${CANDIDATE_TIME_CONTROL} for the candidate"
+            else
+              echo "time_control: ${TIME_CONTROL}"
+            fi
             echo "hash_mb: ${HASH}"
             echo "concurrency: ${CONCURRENCY}"
             echo "startup_ms: ${STARTUP_MS}"
@@ -319,7 +331,8 @@ jobs:
           baseline: ${{ inputs.baseline_name }}
           baseline_sha: ${{ inputs.baseline_sha }}
           shards: ${{ inputs.count }}
-          time_control: ${{ inputs.time_control }}
+          # what the summary prints, so a time odds match says so
+          time_control: ${{ inputs.candidate_time_control && format('{0} against {1}', inputs.candidate_time_control, inputs.time_control) || inputs.time_control }}
           sprt: ${{ inputs.sprt }}
           elo0: ${{ inputs.elo0 }}
           elo1: ${{ inputs.elo1 }}
diff --git a/.github/workflows/strength.yml b/.github/workflows/strength.yml
index 3f689865..643c9f54 100644
--- a/.github/workflows/strength.yml
+++ b/.github/workflows/strength.yml
@@ -72,6 +72,10 @@ on:
         description: The table both sides are given, in MB. 256 is what the engine defaults to. A smaller table puts the replacement policy under the pressure a longer game would, and figures at different sizes are not comparable.
         type: number
         default: 256
+      candidate_time_control:
+        description: A clock for the candidate alone, for a time odds match, where the same build plays itself with one side given more time. The baseline plays time_control. Left empty both sides play time_control.
+        type: string
+        default: ""
   workflow_call:
     inputs:
       candidate:
@@ -112,6 +116,9 @@ on:
       hash_mb:
         type: number
         default: 256
+      candidate_time_control:
+        type: string
+        default: ""
       publish:
         description: Append the result to the release notes for this tag
         type: boolean
@@ -260,6 +267,7 @@ jobs:
       # each other's openings
       seed: ${{ inputs.seed || github.run_id }}
       time_control: ${{ inputs.time_control }}
+      candidate_time_control: ${{ inputs.candidate_time_control }}
       sprt: ${{ fromJSON(needs.resolve.outputs.sprt) }}
       elo0: ${{ fromJSON(needs.resolve.outputs.elo0) }}
       elo1: ${{ fromJSON(needs.resolve.outputs.elo1) }}
@@ -290,6 +298,7 @@ jobs:
       book: ${{ needs.resolve.outputs.book }}
       seed: ${{ inputs.seed || github.run_id }}
       time_control: ${{ inputs.time_control }}
+      candidate_time_control: ${{ inputs.candidate_time_control }}
       sprt: ${{ fromJSON(needs.resolve.outputs.sprt) }}
       elo0: ${{ fromJSON(needs.resolve.outputs.elo0) }}
       elo1: ${{ fromJSON(needs.resolve.outputs.elo1) }}
@@ -320,6 +329,7 @@ jobs:
       book: ${{ needs.resolve.outputs.book }}
       seed: ${{ inputs.seed || github.run_id }}
       time_control: ${{ inputs.time_control }}
+      candidate_time_control: ${{ inputs.candidate_time_control }}
       sprt: ${{ fromJSON(needs.resolve.outputs.sprt) }}
       elo0: ${{ fromJSON(needs.resolve.outputs.elo0) }}
       elo1: ${{ fromJSON(needs.resolve.outputs.elo1) }}
@@ -350,6 +360,7 @@ jobs:
       book: ${{ needs.resolve.outputs.book }}
       seed: ${{ inputs.seed || github.run_id }}
       time_control: ${{ inputs.time_control }}
+      candidate_time_control: ${{ inputs.candidate_time_control }}
       sprt: ${{ fromJSON(needs.resolve.outputs.sprt) }}
       elo0: ${{ fromJSON(needs.resolve.outputs.elo0) }}
       elo1: ${{ fromJSON(needs.resolve.outputs.elo1) }}