From b5e73cbbcf77d8edcd5e5fe4a78dbf2f72915614 Mon Sep 17 00:00:00 2001
From: Simon Gardling <titaniumtown@proton.me>
Date: Wed, 30 Apr 2025 13:52:19 -0400
Subject: [PATCH] elo: improve code quality and add confidence intervals

---
 src/elo.rs | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/elo.rs b/src/elo.rs
index dbd35f0..9ea10c5 100644
--- a/src/elo.rs
+++ b/src/elo.rs
@@ -9,7 +9,7 @@ use indicatif::{ProgressBar, ProgressStyle};
 use rand::seq::SliceRandom;
 use rayon::iter::{IntoParallelIterator, ParallelIterator};
 use skillratings::{
-    glicko2::{glicko2, Glicko2Rating},
+    glicko2::{confidence_interval, glicko2, Glicko2Rating},
     Outcomes, Rating,
 };
 use std::num::NonZero;
@@ -30,7 +30,7 @@ pub fn run() {
         ..Default::default()
     };
 
-    let configs = [2, 4, 6]
+    let configs = [6]
         .into_iter()
         .map(move |d| FutureMoveConfig {
             max_depth: d,
@@ -143,13 +143,22 @@ pub struct PlayerArena {
 impl std::fmt::Display for PlayerArena {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let mut players_i: Vec<usize> = (0..self.players.len()).collect();
-        players_i.sort_by_key(|&i| -(self.players[i].2.rating() * 100.0) as i64);
+
+        players_i.sort_by(|&a, &b| {
+            self.players[b]
+                .2
+                .rating()
+                .total_cmp(&self.players[a].2.rating())
+        });
 
         for i in players_i {
+            let conf_interval = confidence_interval(&self.players[i].2);
+
             writeln!(
                 f,
-                "({:.2}): {}",
+                "({:.2}[+/-{:.2}]): {}",
                 self.players[i].2.rating(),
+                conf_interval.1 - self.players[i].2.rating(),
                 self.players[i].0
             )?;
         }
@@ -163,9 +172,8 @@ impl PlayerArena {
         Self {
             players: players
                 .into_iter()
-                .zip([Default::default()].into_iter().cycle())
-                // flatten tuple
-                .map(|((a, b), c)| (a, b, c))
+                // All starting ratings should be the default
+                .map(|(a, b)| (a, b, Default::default()))
                 .collect(),
         }
     }
@@ -238,9 +246,12 @@ impl PlayerArena {
 
             received_num += 1;
             p.inc(1);
+            // add extra newline after progressbar
             println!();
+
             // break if all pairs were recieved
             if received_num == num {
+                drop(receiver);
                 break;
             }
         }
@@ -265,14 +276,12 @@ impl PlayerArena {
     }
 
     fn process_outcome(&mut self, player1: usize, player2: usize, outcome: &Outcomes) {
-        let (np1, np2) = glicko2(
+        (self.players[player1].2, self.players[player2].2) = glicko2(
             &self.players[player1].2,
             &self.players[player2].2,
             outcome,
             &Default::default(),
         );
-        self.players[player1].2 = np1;
-        self.players[player2].2 = np2;
     }
 
     fn play_two_inner(player_1: Box<dyn Agent>, player_2: Box<dyn Agent>) -> Outcomes {