How the Ranking Works Without Comparing Everything
Steam Wishlist Ranker can rank a wishlist of hundreds of games in a few minutes to a little over ten. Why is it so fast? This article explains what the tool does under the hood, with a bit of math.
Comparing everything isn't realistic
The most thorough way to rank is a round robin: compare every game against every other game. The number of comparisons grows roughly with the square of the list size.
| Games | Round-robin matchups | At 3 seconds each |
|---|---|---|
| 50 | 1,225 | About 1 hour |
| 100 | 4,950 | About 4 hours |
| 274 | 37,401 | About 31 hours |
Even an efficient sorting algorithm, the kind computers use, needs around 2,000 comparisons for 274 games. That's still over an hour and a half, and your focus runs out long before.
Only the top of the order really matters
Here's the shift in thinking. A wishlist order is useful when you decide what to buy next. At that moment you look at the top few to few dozen games. The difference between #150 and #151 barely matters.
So the tool is built to compare carefully at the top and roughly further down. It spends your comparisons where the order actually means something.
Four stages
1. Narrow down with taps
First, you tap the games that catch your eye in a grid. Picked games get a higher starting score and the rest get a lower one. Without a single head-to-head, the whole list splits into "top candidates" and "everything else". It's the fastest stage, and most people can do it without hesitation.
2. Two picks out of four
In the qualifiers you see four games and pick the most wanted, then the least wanted. Four games make six possible pairs, and those two taps settle five of them: the most wanted beats the other three, and the least wanted loses to the other three. Only the pair in the middle stays unknown.
Six comparisons for the price of two taps. That's the main reason hundreds of games take so little time.
Wins and losses turn into scores using an approach close to the Elo rating used in chess. Beating a strong opponent raises a score a lot; losing to a weak one drops it a lot. Each lap settles the scores further, and when the top group stops changing, it's time to move on.
3. 1-on-1 for the top games only
Only the top games from the qualifiers go into 1-on-1 duels. This is where the order matters most, so it's done one pair at a time. The tool avoids repeating the same pairs, so each duel teaches it something new.
This stage includes challengers. Now and then, a game you didn't tap at the start crashes in and challenges the top. It's how games that sank on a first impression get a second chance. Challengers are drawn from games that sat high on your original Steam list, games on sale, and games you added recently. A win puts the challenger just above the game it beat and sets up a match against someone stronger.
4. The final bracket
Finally, the top 16 play a seeded bracket. Fifteen matches decide your #1 and sharpen the order at the top, where scores alone tend to be close. Direct matchups settle it.
Finishing: the middle and the bottom
After your #1 is decided, you can optionally tidy the middle and the bottom. These also use groups of four in a knockout format: pick the most wanted in the middle, the least wanted at the bottom. Games that keep being picked as least wanted end up in the "Probably skip" tier.
These finishing steps only reorder games within each group, so they never disturb the order you settled at the top.
Summary
- A round robin of 274 games takes over 37,000 matchups. Not realistic.
- Shopping only needs the top of the order, so the effort goes there.
- Picking 2 out of 4 settles 5 of 6 pairs at once.
- Challengers give overlooked games a second chance.
- A final bracket decides the close calls at the top head to head.
Knowing how it works makes it more fun to wonder why a particular challenger showed up.