From 27befeb92bfe6693dad2c2c8691d21fdb53819a6 Mon Sep 17 00:00:00 2001
From: Play Life Bot <bot@playlife.local>
Date: Fri, 2 Jan 2026 16:50:40 +0300
Subject: [PATCH] Refactor group 2 word selection: use (failure+1)/(success+1)
 ratio, bump version to 2.8.0

---
 VERSION                   | 2 +-
 play-life-backend/main.go | 9 ++++-----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/VERSION b/VERSION
index a4dd9db..834f262 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.7.4
+2.8.0
diff --git a/play-life-backend/main.go b/play-life-backend/main.go
index b533c96..6b5e83d 100644
--- a/play-life-backend/main.go
+++ b/play-life-backend/main.go
@@ -1123,7 +1123,7 @@ func (a *App) getTestWordsHandler(w http.ResponseWriter, r *http.Request) {
 		group1WordIDs[word.ID] = true
 	}
 
-	// Group 2: (failure - success) >= 5, sorted by (failure - success) DESC, then last_success_at ASC (NULL first)
+	// Group 2: sorted by (failure + 1)/(success + 1) DESC, take top 40%
 	// Exclude words already in group1
 	group2Exclude := ""
 	group2Args := make([]interface{}, 0)
@@ -1142,15 +1142,14 @@ func (a *App) getTestWordsHandler(w http.ResponseWriter, r *http.Request) {
 	group2Query := `
 		SELECT ` + baseSelect + `
 		` + baseFrom + `
-		AND (COALESCE(p.failure, 0) - COALESCE(p.success, 0)) >= 5
 		` + group2Exclude + `
 		ORDER BY 
-			(COALESCE(p.failure, 0) - COALESCE(p.success, 0)) DESC,
+			(COALESCE(p.failure, 0) + 1.0) / (COALESCE(p.success, 0) + 1.0) DESC,
 			CASE WHEN p.last_success_at IS NULL THEN 0 ELSE 1 END,
 			p.last_success_at ASC
 		LIMIT $` + fmt.Sprintf("%d", len(group2Args)+1)
 	
-	group2Args = append(group2Args, group2Count*2) // Get more to ensure uniqueness
+	group2Args = append(group2Args, group2Count)
 	group2Rows, err := a.DB.Query(group2Query, group2Args...)
 	if err != nil {
 		sendErrorWithCORS(w, err.Error(), http.StatusInternalServerError)
@@ -1160,7 +1159,7 @@ func (a *App) getTestWordsHandler(w http.ResponseWriter, r *http.Request) {
 
 	group2Words := make([]Word, 0)
 	group2WordIDs := make(map[int]bool)
-	for group2Rows.Next() && len(group2Words) < group2Count {
+	for group2Rows.Next() {
 		var word Word
 		var lastSuccess, lastFailure sql.NullString