JSFiddle - React, Tailwind, and code Playground

JavaScript

<?php


include('mysql.php');
include('functions.php');

$winnerId = $_POST['winner'];

if ($_POST['winner'] == $_POST['first']){
    $looser = $_POST['second'];}
    else { $looser = $_POST['second']; 

    // POST the winner
    $result = mysql_query("SELECT * FROM images WHERE image_id = ".$_POST['first']." ");
    $winner = mysql_fetch_object($result);


    // POST the looser
    $result = mysql_query("SELECT * FROM images WHERE image_id = ".$_POST['second']." ");
    $looser = mysql_fetch_object($result);


    // Update the winner score
    $winner_expected = expected($looser->score, $winner->score);
    $winner_new_score = win($winner->score, $winner_expected);
        //test print "Winner: ".$winner->score." - ".$winner_new_score." - ".$winner_expected."<br>";
    mysql_query("UPDATE images SET score = ".$winner_new_score.", wins = wins+1 WHERE image_id = ".$_POST['first']);


    // Update the looser score
    $looser_expected = expected($winner->score, $looser->score);
    $looser_new_score = loss($looser->score, $looser_expected);
        //test print "looser: ".$looser->score." - ".$looser_new_score." - ".$looser_expected."<br>";
    mysql_query("UPDATE images SET score = ".$looser_new_score.", losses = losses+1  WHERE image_id = ".$_POST['second']);


    // Insert battle
    mysql_query("INSERT INTO battles SET winner = ".$_POST['first'].", looser = ".$_POST['second']." ");


    // Back to the frontpage
    header('location: /');
    
}


?>