- Who has the best stolen bases matchup today (Tuesday, July 21, 2026)?
- Chandler Simpson (TB) — top of the board at 100, facing RHP Kevin Gausman. An elite bat with a green light and the volume to use it is what pushes it to No. 1.
- What are the best MLB stolen bases matchups today (Tuesday, July 21, 2026)?
- The top stolen bases matchups on Tuesday, July 21, 2026: Chandler Simpson (100), Nasim Nuñez (68), Cedric Mullins (58), José Caballero (58), Sung-Mun Song (54). The full board ranks every hitter in every game by stolen bases upside.
- Which hitters have a platoon edge today?
- Chandler Simpson (TB) — lefty bat vs RHP, .075 against righties this year. Nasim Nuñez (WSH) — lefty bat vs RHP, .112 against righties this year. Cedric Mullins (TB) — lefty bat vs RHP, .041 against righties this year. Sung-Mun Song (SD) — lefty bat vs RHP, .106 against righties this year. Jakob Marsee (MIA) — lefty bat vs RHP, .043 against righties this year.
- How is the stolen bases matchup score calculated?
- It's a weighted read of the hitter's stolen bases per plate appearance against the hand he's facing — the last two weeks, the current season, and a two-year baseline, with recent form counting most. Then it folds in the opposing bullpen, his expected plate appearances from the batting order, and park and weather. Scores are set 0–100 across the day's slate, so the best matchup is always 100.
- What does SB/PA mean?
- Stolen bases per plate appearance — a steal-rate proxy that surfaces the real base-stealers. It's a rare event (league average is tiny), so this board is about who actually runs: an active threat sits well above the pack. Driven mostly by the runner, since pitcher/catcher steal-suppression isn't in the feed yet.
- What does the score actually mean?
- Higher is better for the hitter. 80s and 90s mean the bat, the pitcher, and the park all line up. 40s and 50s mean it's neutral to tough. It's a ranking of how today's spots stack up against each other — not the odds of a stolen base.
- What's the confidence meter?
- It's how much data is behind the call — sample size on both the hitter and the pitcher, plus whether the lineup's official. A high score with low confidence is a thinner read than the same score backed by a deep track record. It's not a probability of a stolen base.
- What is a platoon split (handedness split)?
- Most hitters do better against the opposite hand — a lefty bat vs. a righty arm, and vice versa. That gap is the platoon split. The score leans hard on each hitter's rate against the hand he's facing today, which is why the same guy can rank very differently day to day.
- What are park factors?
- Parks aren't neutral. Dimensions, altitude, and weather make some easier to hit in than others. Above 1.00 bumps the score, below 1.00 trims it — same hitter, higher grade in a hitter's park than a pitcher's.
- What do "2W", "SZN" and "2Y" mean?
- The timeframes behind each rate: the last two weeks (recent form), the current season, and a trailing two years (a stable baseline). Recent form counts most, and small samples get pulled toward league average so a hot week doesn't fool the model.
- What do "≈ est", "Due" and "Not starting" mean?
- "≈ est" is a hitter we don't have splits for yet — a rookie or unmatched ID — shown at a league-baseline estimate instead of dropped. "Due" means he hasn't recorded a stolen base in a while and profiles for regression. "Not starting" means he was projected but didn't make the official lineup, so he slides to the bottom where you can still look him up.
- Can I use this for stolen bases props or DFS?
- That's what it's built for — pre-slate research. The board surfaces which hitters have the best conditions today, and where one exists, we show the book's "1+ HR" line so you can shop the price. We're not a sportsbook and we don't post picks — we show the matchup data, the line, and the result. (Best-price and all-book odds are a Pro feature.)
- How accurate is the model?
- We grade every board against real results, and the top of the board lands a stolen base a lot more often than the slate as a whole. Weights get re-tuned weekly against actual outcomes on a held-out split, and since results sit next to projections, you can audit the hit rate yourself on any past date.
- When do lineups update?
- Projected lineups (marked "Proj") come from each team's last game. Official lineups usually drop about two hours before first pitch, and the board updates itself as they post. Batting order is a big driver, so it's worth a second look mid-afternoon — rankings shift as lineups lock.
- Is MatchWiz free?
- Yes. The full board, every game page, and the daily archive are free, no login. Best-price odds and the betting tools are the paid tier.
