Fixes the grand pix site from erroring. Requires either TamperMonkey or GreaseMonkey for Chrome or Firefox respectively.

FixSteamGrandPix.user.js

// ==UserScript==
// @name         [Steam] Fix Grandpix
// @version      1.0
// @description  Fix Valve being bad.
// @author       You
// @match        https://store.steampowered.com/grandprix
// @grant        none
// @run-at       document-body
// ==/UserScript==

// Original function called to start the thing
var ogUpdateTeamScoresWithData = window.UpdateTeamScoresWithData

// Override their function with ours that fixes their bad data
window.UpdateTeamScoresWithData = function(data) {
  data.scores = data.scores.map(score => {
    score.score_dist = +score.score_dist; // converts string to int
    return score;
  })

  // Call the original function with the fixed data
  ogUpdateTeamScoresWithData(data);
}