Score a bracket fairly

Now your app knows who each player picked. Let’s compare predictions with a completed fictional tournament.

1. Read the scoring rules

The existing arrays define the point value of each round:

Round	Games	Points per correct pick	Maximum
Quarterfinals	4	1	4
Semifinals	2	2	4
Championship	1	4	4
Total	7		12

The correct results are stored in OFFICIAL_RESULTS. Never change the correct results to match the current user’s picks.

2. Implement scorePicks(pickMap)

This function should return a number. It must not alter the supplied picks.

Start with:

function scorePicks(pickMap) {
  let points = 0;
  for (const [gameKey, winnerId] of Object.entries(OFFICIAL_RESULTS)) {
    const round = Number(gameKey.split('-')[0]);
    if (pickMap[gameKey] === winnerId) {
      points += ROUND_POINTS[round];
    }
  }
  return points;
}

The key idea is the comparison. A prediction earns points only if it matches the correct winner for that exact game.

3. Check the boundaries

For debugging, try a bracket with no picks:

console.log(scorePicks({})); // Expected: 0

Then test all the correct results:

console.log(scorePicks(OFFICIAL_RESULTS)); // Expected: 12

Try a partially correct bracket and calculate its points by hand before running the function.

4. Show the current player’s score

Wire the existing “Score my picks” button to update #score-status using textContent. Use clear wording: these are sample results, not live basketball scores.

Checkpoint

Choose Check this step. It verifies that zero picks earn zero, all correct picks earn 12, and partial results earn the appropriate weighted points.

Discussion: Why is a championship pick worth more than a quarterfinal pick? How would a different scoring system affect leaderboard strategy?

Review the JavaScript lesson.