How to Play Run The Diamond

Draft an all-time MLB roster, build a contender, and chase the perfect season: the 116-win record and a World Series ring.

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The twelve spots

You fill a full lineup and pitching staff: catcher, four infielders (1B, 2B, 3B, SS), three outfielders (LF, CF, RF), a designated hitter, two starting pitchers, and a closer.

C 1B 2B 3B SS LF CF RF DH SP SP CL

The rules

Spin. Each spin draws a random team-season from MLB history (1901-2025). You see that roster and draft one player who fits an open spot.
Budget. You have $190M to fill all twelve spots. Prices come from WAR, so superstars cost a premium and you can't stack legends everywhere. The budget always reserves enough to fill your open positions.
Re-spin. Don't like the draw? Re-spin for a rising fee ($5M, then $10M, then $15M), up to three times.
Chemistry. Teammates from the same team-season, franchise loyalists, double-play combos, real batterymates, players from the same college, and actual families (the Alous, the Griffeys) raise your chemistry multiplier.
Roster shape. Talent isn't everything. Balance between bats and arms, a strong floor, and no boom-or-bust over-reliance all make your roster play better. Your build earns an archetype like Murderers' Row or No Weak Links.
Play 162. Your roster simulates a full season against real all-time opponents (the 1927 Yankees, the 2019 Astros) with a 14-game marquee gauntlet mixed in.
Playoffs. Win enough and you reach October: the Division Series, Championship Series, and the World Series, and the deepest rounds get harder the weaker your team is. A team rated 95 or better plays like one: it should reach the World Series most years.
The chase. 116 wins ties the all-time record; 117+ makes you the greatest of all time.

How you're rated

Every roster gets a team rating from 1 to 99. It says how many wins the roster projects to, and 99 is the best roster the budget can buy.

It also gets a rank against real MLB teams. That compares your roster's talent on paper with every real team-season since 1901. It is not your place on the leaderboard. A roster of twelve star seasons outranks most real clubs, so a high number here is common.

A title isn't just about getting hot. The championship stiffens against weaker teams, so winning it all means you truly built a great club.

Achievements

207 badges span milestones, winning, October, real-team rankings, roster craft, the roster itself, the modes, the daily and streaks. Badges are for signed-in players. Every season you play signed in counts, and seasons played as a guest do not. A new badge lights the moment you qualify, including for seasons you played before it existed.

Where the numbers come from

Player value is based on Wins Above Replacement (WAR) from Baseball-Reference, covering every season from 1901 to 2025. FanGraphs rates the same season differently, so a number you look up elsewhere may not match.

Two other things make a figure on a card differ from a season total. A starter who threw more than 210 innings is priced and rated on what he did in 210, and his card names that figure, while the WAR beside his name is his whole year. And a two-way season is two cards, one for the bat and one for the arm, so each carries half the year.

This is an unofficial fan project, not affiliated with or endorsed by MLB or any club.

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