Baseball Stats Explained: A Guide for Parents & New Fans

You're in a folding chair behind the backstop when another parent leans over and says your kid "had a great OBP day." You nod. You have no idea what that means.

Here's baseball stats explained without the jargon: the sport tracks hundreds of statistics, and you need roughly eight of them. Three are already printed on the scoreboard in front of you.

The numbers look intimidating because nobody designed them. They piled up over 150 years, one abbreviation at a time, and broadcasts flash them on screen without explaining them. Below: what each one means, what counts as good, and which ones are useless for judging a 12-year-old.

Start With the Scoreboard

Every scoreboard, from a Little League field to a big league park, ends with the same three letters: R, H, E. Runs, hits, errors. Runs decide the game; the other two tell you how it got that way. A 4-1 game with 12 hits reads very differently from a 4-1 game with three errors.

Below that sits the count, always balls first. "3-2" is three balls and two strikes — one pitch from either a walk or a strikeout. Outs are tracked separately, usually as lights.

That's the entire live scoreboard. On a scorecard, Little League's scorekeeping guide adds one layer: fielders are numbered 1 through 9, pitcher to right field. That's why "6-4-3" means shortstop to second to first — the classic double play.

Batting Average (AVG)

Hits divided by at-bats. Go 3-for-10 and you're hitting .300.

The problem, which MLB's own glossary admits, is that batting average ignores walks entirely and treats every hit the same. A bunt single and a grand slam both count as one hit. And because a walk isn't an at-bat, a player can walk four times in a game without moving his average a point.

In 2025 the average major league hitter batted .245. Aaron Judge led the majors at .331.

On-Base Percentage (OBP)

How often a hitter avoids making an out. Hits, walks and hit-by-pitches all count, divided by plate appearances.

The gap shows up fast. A player who goes 2-for-4 with a walk has a .500 batting average but a .600 on-base percentage — he reached three times in five trips. Outs are the only clock baseball has, so a hitter who refuses to make them is doing his job.

Dodgers executive Branch Rickey and statistician Allan Roth invented OBP in the 1940s, but MLB didn't make it official until 1984. League average in 2025: .315.

Slugging Percentage (SLG)

Total bases divided by at-bats — a single counts one, a double two, a triple three, a home run four.

Despite the name it isn't a percentage; it's an average, and it can climb above 1.000. Where on-base percentage asks "did he reach?", slugging asks "how far did he get?" League average in 2025: .404.

OPS: The One Number to Remember

OPS is on-base percentage plus slugging percentage. You just add them.

Adding two numbers with different denominators is mathematically sloppy. It also works — and unlike the fancier metrics, you can do it in your head.

The easiest way to read OPS is as a report card. .900 and up is an A. The .800s are a B. The .700s are a C. Below .700 you're fighting for a roster spot. League average in 2025 was .719, and FanGraphs' reference scale puts .800 at above average and 1.000 at excellent.

If you learn one number beyond the scoreboard, make it this one. The top of the OPS leaderboard is always the best hitters in baseball — which is not true of batting average or home runs.

ERA: What "Earned" Actually Means

Earned run average is earned runs times nine, divided by innings pitched. It answers one question: if this pitcher threw a full nine innings, how many runs would he typically give up?

The word doing the work is earned. A ground ball goes through the second baseman's legs and that runner later scores — unearned, and it never touches the pitcher's ERA. Runs scoring on an error or a passed ball don't count against him; everything else does.

One trap: innings pitched are written in thirds. "115.1 innings" means 115 and one-third, not 115.1. Type it straight into a calculator and your math comes out wrong.

League average in 2025 was 4.15. Paul Skenes led the majors at 1.97, less than half.

WHIP: Traffic on the Basepaths

Walks plus hits, divided by innings pitched. It asks the simplest question in pitching: how many runners does this guy put on per inning?

A WHIP of 1.50 means about three baserunners every two innings. Under 1.10 is excellent. League average in 2025 was 1.289. Small piece of trivia — baseball didn't invent WHIP. Daniel Okrent, who also invented fantasy baseball, made it up in 1979.

RBI and Pitcher Wins: Two Stats to Retire

Both of these mostly measure your teammates.

An RBI requires somebody already standing on base. Hit a triple with the bases empty and you've done nearly all the work of scoring — you're ninety feet away — and get credited with nothing. Worse: a hitter who drives in 50 of his 100 chances finishes with 50 RBI, while one who converts 100 of 300 finishes with 100. The second player looks twice as productive and was worse at the job.

Pitcher wins are shakier still. A starter can throw eight scoreless innings and take the loss, or give up seven runs and get the win. In 2018 Jacob deGrom posted a 1.70 ERA, finished 10-9, and won the Cy Young Award anyway.

Neither number is a lie. They're just poor tools for comparing players, and worse ones for evaluating a kid.

WAR: One Number for Everything

Wins Above Replacement rolls hitting, baserunning, fielding, position and playing time into one figure: how many more games did a team win by playing this guy instead of a replacement-level fill-in? Roughly, 2 is a solid everyday starter, 5 an All-Star, 6 or more an MVP candidate.

One catch worth knowing: replacement level is not league average. A 0.0 WAR player is closer to a minor league call-up, and that's the most common misunderstanding about the stat.

Exit Velocity: The Stat That Sees Through Luck

Exit velocity is how fast the ball leaves the bat. Statcast calls anything at 95 mph or harder a hard-hit ball; the typical qualified major leaguer in 2025 averaged about 89.7 mph.

Why it matters: a weak flare can drop in for a game-winning double, and a perfectly struck line drive can die on the warning track. Batting average records the outcome, exit velocity records the swing. When a hitter's average is ugly but he keeps crushing the ball, the average is the number that's wrong.

What Counts as Good: 2025 Benchmarks

Every stat above is meaningless without a reference point. These are the actual 2025 major league figures, not rules of thumb — and they're major league numbers, so don't hold a 14-year-old to them.

Why Your Kid's Stat Line Isn't What You Think

Here's what nobody tells parents. At the youth level, the person deciding whether that ground ball was a hit or an error is another parent with a phone, scoring live, under pressure to be ready before the next pitch.

One volunteer who has scored around a thousand youth games put it bluntly: he records what he sees, in the moment, and the only numbers you can trust every time are pitch count, balls and strikes, and the final score. Everything else runs through a judgment call.

Those calls aren't consistent between teams. Some scorers rule an error any time an infielder gets a glove on the ball; some 9U teams record no errors at all and credit every runner with a hit. Coaches have gone back after games and changed a reached-on-error to a hit to protect a slumping kid's confidence. Whether you find that kind or dishonest, it tells you what youth statistics really are: a motivational tool that happens to look like a measurement.

So when the app says your daughter is hitting .280, the honest reading is "somewhere in that neighborhood, as judged by a rotating cast of volunteers."

40 At-Bats Is Not a Sample Size

Even if the scoring were flawless, the sample is too small to mean anything. A youth player might get 40 to 60 at-bats across a season. At 50 at-bats, the difference between hitting .240 and .400 is eight hits spread over three months — move four ground balls two feet either way and the whole season "changes."

Major League Baseball understands this, which is why it enforces a minimum: a hitter needs 3.1 plate appearances per scheduled game — 502 over a full season — before he's eligible for a batting title. Your kid will not see 502 at-bats before graduation.

So don't read your child's batting average in June. Watch whether the at-bats are improving — deeper counts, harder contact, fewer swings at pitches out of the zone. Those show up months before the average does.

The Short Version

That's baseball stats explained in about ten minutes. On the scoreboard, read R, H and E, and remember the count goes balls first. For hitters, on-base percentage beats batting average and OPS beats both — .800 is a good day, .900 a great one. For pitchers, ERA and WHIP cover almost everything, and lower is better on both.

Skip RBI and pitcher wins when sizing up a player; both depend on eight other people. And when the numbers belong to your own kid, hold them loosely — a volunteer recorded them under time pressure, across a sample too small to conclude anything. Watch the at-bats instead. The stats will catch up.