From e642eb535efa661118023a0c1db70f385ab987f3 Mon Sep 17 00:00:00 2001
From: Luc Mcgrady <lucmcgrady@gmail.com>
Date: Thu, 5 Jun 2025 23:03:39 +0100
Subject: [PATCH] Adjusted loss values

---
 proto/anki/scheduler.proto                |  2 +-
 rslib/src/scheduler/fsrs/params.rs        | 34 ++++++++++++++++++++---
 rslib/src/scheduler/service/mod.rs        |  2 +-
 ts/routes/deck-options/FsrsOptions.svelte | 10 ++-----
 4 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/proto/anki/scheduler.proto b/proto/anki/scheduler.proto
index 56708ddfb..b02315dd3 100644
--- a/proto/anki/scheduler.proto
+++ b/proto/anki/scheduler.proto
@@ -360,7 +360,7 @@ message ComputeFsrsParamsRequest {
 message ComputeFsrsParamsResponse {
   repeated float params = 1;
   uint32 fsrs_items = 2;
-  optional float log_loss = 3;
+  optional bool health_check_passed = 3;
 }
 
 message ComputeFsrsParamsFromItemsRequest {
diff --git a/rslib/src/scheduler/fsrs/params.rs b/rslib/src/scheduler/fsrs/params.rs
index d6853ca4e..6e99c50ce 100644
--- a/rslib/src/scheduler/fsrs/params.rs
+++ b/rslib/src/scheduler/fsrs/params.rs
@@ -51,6 +51,18 @@ pub(crate) fn ignore_revlogs_before_ms_from_config(config: &DeckConfig) -> Resul
     ignore_revlogs_before_date_to_ms(&config.inner.ignore_revlogs_before_date)
 }
 
+/// r: retention
+fn log_loss_adjustment(r: f32) -> f32 {
+    0.621 * (4. * r * (1. - r)).powf(0.739)
+}
+
+/// r: retention
+///
+/// c: review count
+fn rmse_adjustment(r: f32, c: u32) -> f32 {
+    0.0417 / (r.powf(1.63) - 1.41) + 0.125 / ((c as f32 / 1000.).powf(0.655) + 1.22) + 0.102
+}
+
 impl Collection {
     /// Note this does not return an error if there are less than 400 items -
     /// the caller should instead check the fsrs_items count in the return
@@ -77,7 +89,7 @@ impl Collection {
             return Ok(ComputeFsrsParamsResponse {
                 params: current_params.to_vec(),
                 fsrs_items,
-                log_loss: None,
+                health_check_passed: None,
             });
         }
         // adapt the progress handler to our built-in progress handling
@@ -149,11 +161,25 @@ impl Collection {
             }
         }
 
-        let log_loss = if health_check {
+        let health_check_passed = if health_check {
             let fsrs = FSRS::new(None)?;
             fsrs.evaluate_with_time_series_splits(input, |_| true)
                 .ok()
-                .map(|eval| eval.log_loss)
+                .map(|eval| {
+                    let r = items.iter().fold(0, |p, item| {
+                        p + (item
+                            .reviews
+                            .last()
+                            .map(|reviews| reviews.rating)
+                            .unwrap_or(0)
+                            > 1) as u32
+                    }) as f32
+                        / fsrs_items as f32;
+                    let adjusted_log_loss = eval.log_loss / log_loss_adjustment(r);
+                    let adjusted_rmse = eval.rmse_bins / rmse_adjustment(r, fsrs_items);
+
+                    adjusted_log_loss < 1.10 && adjusted_rmse < 1.58
+                })
         } else {
             None
         };
@@ -161,7 +187,7 @@ impl Collection {
         Ok(ComputeFsrsParamsResponse {
             params,
             fsrs_items,
-            log_loss,
+            health_check_passed,
         })
     }
 
diff --git a/rslib/src/scheduler/service/mod.rs b/rslib/src/scheduler/service/mod.rs
index fde64007f..50607ffbb 100644
--- a/rslib/src/scheduler/service/mod.rs
+++ b/rslib/src/scheduler/service/mod.rs
@@ -376,7 +376,7 @@ impl crate::services::BackendSchedulerService for Backend {
         Ok(ComputeFsrsParamsResponse {
             params,
             fsrs_items,
-            log_loss: None,
+            health_check_passed: None,
         })
     }
 
diff --git a/ts/routes/deck-options/FsrsOptions.svelte b/ts/routes/deck-options/FsrsOptions.svelte
index 684c6711b..d06c09eb5 100644
--- a/ts/routes/deck-options/FsrsOptions.svelte
+++ b/ts/routes/deck-options/FsrsOptions.svelte
@@ -41,7 +41,6 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     const defaults = state.defaults;
     const fsrsReschedule = state.fsrsReschedule;
     const daysSinceLastOptimization = state.daysSinceLastOptimization;
-    const logLossBadThreshold = 0.5;
 
     $: lastOptimizationWarning =
         $daysSinceLastOptimization > 30 ? tr.deckConfigTimeToOptimize() : "";
@@ -191,13 +190,10 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
                             )) ||
                         resp.params.length === 0;
 
-                    const highLogLoss =
-                        resp.logLoss && resp.logLoss > logLossBadThreshold;
+                    const health_check_passed =
+                        resp.healthCheckPassed && !resp.healthCheckPassed;
 
-                    if (resp.logLoss) {
-                        console.log(`FSRS-test-train-split-log-loss = ${resp.logLoss}`);
-                    }
-                    if (highLogLoss) {
+                    if (health_check_passed) {
                         setTimeout(() => alert(tr.deckConfigFsrsBadFitWarning()));
                     } else if (already_optimal) {
                         const msg = resp.fsrsItems