Leaderboard: rank only at 5+ rounds (fairness)

game/ui.py

@@ -21,6 +21,7 @@ from . import deck as deck_mod
 
 TIER_COLOR = {"SAFE": "#2f6b2b", "CAUTION": "#87671c", "DEADLY": "#8c1d14", "UNKNOWN": "#57544c"}
 _LB_COLS = ["Player", "You %", "Machine %", "Rounds"]
+MIN_RANK_ROUNDS = 5   # ranked only after 5 rounds, so a 1-round 100% can't top the board
 
 
 def _machine_call(pipe, path: str):
@@ -85,7 +86,7 @@ def _lb_df() -> pd.DataFrame:
     data = []
     for r in datastore.load_leaderboard():
         t = int(r.get("skill_total", 0) or 0)
-        if t == 0:
+        if t < MIN_RANK_ROUNDS:
             continue
         data.append([
             r.get("contributor", "?"),
@@ -125,7 +126,7 @@ def build_game_tab(pipe) -> None:
 
     score_html = gr.HTML(_scoreboard({"you": 0, "machine": 0, "total": 0}))
 
-    gr.HTML("<div class='gm-divider'>▌ LEADERBOARD</div>")
+    gr.HTML("<div class='gm-divider'>▌ LEADERBOARD · ranked at 5+ rounds</div>")
     post_btn = gr.Button("POST MY SCORE", elem_classes="eink-scan")
     lb_status = gr.HTML("")
     lb = gr.Dataframe(value=_lb_df(), headers=_LB_COLS, interactive=False,