Baseball Stats Abbreviations Guide for Parents: Every Acronym Decoded

What it stands for: Batting Average

Formula: Hits ÷ At-Bats (excluding walks, sacrifices, and hit-by-pitches)

Plain English: How often a batter gets a hit when they swing. A .300 average means they get a hit 3 out of every 10 at-bats.

What's good: .300+ is excellent (All-Star level). .270-.299 is very good. .250-.269 is average. Below .230 is struggling.

Youth baseball note: In 8U-12U, averages are inflated because of weaker pitching. A .500 average in rec ball doesn't mean the same thing as a .300 in high school. Focus on improvement, not the number.

Example: A player with 40 hits in 120 at-bats has a .333 average — that's excellent at any level.

What it stands for: On-Base Percentage

Formula: (Hits + Walks + Hit By Pitch) ÷ (At-Bats + Walks + Hit By Pitch + Sacrifice Flies)

Plain English: How often a batter reaches base by any means — hits, walks, or getting hit by a pitch. This is a better measure of offensive value than batting average because it includes walks.

What's good: .400+ is elite. .360-.399 is excellent. .330-.359 is above average. .320 is average.

Why it matters for your kid: A player who walks a lot is just as valuable as a player who hits .300. Teach your kid to value the walk — getting on base is the most important offensive skill.

Example: A player hitting .280 with a .400 OBP is reaching base 40% of the time — that's more valuable than a .300 hitter with a .330 OBP.

What it stands for: Slugging Percentage

Formula: Total Bases ÷ At-Bats (singles = 1, doubles = 2, triples = 3, home runs = 4)

Plain English: How much power a hitter has. It measures not just how often they get hits, but how many bases they get per hit.

What's good: .550+ is elite (MVP level). .500-.549 is excellent. .450-.499 is very good. .400-.449 is average.

Youth baseball note: In 8U-12U, slugging is less meaningful because fielding errors lead to extra bases. Focus on hard contact rather than slugging percentage.

Example: A player with 50 total bases in 100 at-bats has a .500 slugging percentage — that's very good power.

What it stands for: On-Base Plus Slugging

Formula: OBP + SLG

Plain English: The most common single-number measure of a hitter's overall value. It combines how often they get on base with how much power they have.

What's good: 1.000+ is elite (MVP level). .900-.999 is excellent. .800-.899 is very good. .700-.799 is average.

Why it matters: OPS is the stat most MLB front offices use as a quick measure of offensive production. If your kid's OPS is over .800, they're producing.

Example: A .400 OBP + .500 SLG = .900 OPS — that's an excellent hitter at any level.

What it stands for: Isolated Power

Formula: SLG - AVG

Plain English: Measures a hitter's raw power by removing singles from the equation. A high ISO means a player hits for extra bases (doubles, triples, home runs).

What's good: .250+ is elite power. .200-.249 is excellent. .150-.199 is above average. .100-.149 is average.

Example: A .300 hitter with a .600 SLG has an ISO of .300 — that's elite power. A .300 hitter with a .400 SLG has an ISO of .100 — that's a singles hitter.

What it stands for: Batting Average on Balls In Play

Formula: (Hits - Home Runs) ÷ (At-Bats - Strikeouts - Home Runs + Sacrifice Flies)

Plain English: Measures how often a batter gets a hit when they put the ball in play (excluding home runs and strikeouts). A high BABIP suggests a player is getting lucky; a low BABIP suggests bad luck.

What's normal: Around .300 is average. Above .350 is lucky (or the player hits the ball very hard). Below .250 is unlucky.

Youth baseball note: BABIP is less useful in youth baseball because fielding is inconsistent. A hard ground ball that should be an out might be an error — inflating BABIP.

What it stands for: Weighted On-Base Average

Plain English: Like OBP, but it gives more credit for extra-base hits. A home run is worth more than a single, which makes sense — a home run is more valuable.

What's good: .400+ is elite. .370-.399 is excellent. .340-.369 is above average. .320 is average.

Why it matters: wOBA is the stat that advanced analytics use instead of batting average. It's a better measure of a hitter's true value.

What it stands for: Earned Run Average

Formula: (Earned Runs × 9) ÷ Innings Pitched

Plain English: How many runs a pitcher would give up if they pitched a full 9-inning game. The lower, the better.

What's good: Under 3.00 is elite. 3.00-3.50 is excellent. 3.50-4.00 is very good. 4.00-4.50 is average. Over 5.00 is below average.

Youth baseball note: In 8U-12U, ERAs are typically higher because of walks and errors. A 4.00 ERA in 10U travel ball is actually quite good.

Example: A pitcher who gives up 3 earned runs in 6 innings has a 4.50 ERA (3 × 9 ÷ 6 = 4.50).

What it stands for: Walks + Hits per Inning Pitched

Formula: (Walks + Hits) ÷ Innings Pitched

Plain English: How many baserunners a pitcher allows per inning. It's the best measure of a pitcher's control and effectiveness.

What's good: Under 1.00 is elite. 1.00-1.10 is excellent. 1.10-1.20 is very good. 1.20-1.30 is average. Over 1.50 is struggling.

Why it matters for your kid: WHIP is the single best stat for youth pitchers. If your kid has a WHIP under 1.20, they're throwing strikes and keeping runners off base — that's the formula for success at any level.

Example: A pitcher who allows 8 hits and 3 walks in 10 innings has a 1.10 WHIP — that's excellent.

What it stands for: Strikeouts per 9 Innings

Formula: (Strikeouts × 9) ÷ Innings Pitched

Plain English: How many batters a pitcher strikes out per full game. Higher is better.

What's good: 10+ is elite. 8-10 is excellent. 6-8 is above average. 5-6 is average.

Youth baseball note: In 8U-10U, K/9 is often very high because batters are still learning to hit. By 12U+, it becomes a meaningful measure of a pitcher's stuff.

What it stands for: Walks per 9 Innings

Formula: (Walks × 9) ÷ Innings Pitched

Plain English: How many batters a pitcher walks per full game. Lower is better — walks are the enemy of good pitching.

What's good: Under 2.0 is elite. 2.0-2.5 is excellent. 2.5-3.0 is above average. 3.0-4.0 is average. Over 5.0 is a problem.

Why it matters for your kid: BB/9 is the most important stat for youth pitchers. If your kid walks 4+ batters per 9 innings, they need to work on command. Walks kill teams in travel ball.

What it stands for: Fielding Independent Pitching

Plain English: What a pitcher's ERA would be if the defense behind them was average. It only considers strikeouts, walks, hit-by-pitches, and home runs — things the pitcher controls.

What's good: Under 3.00 is elite. 3.00-3.50 is excellent. 3.50-4.00 is above average. 4.00-4.50 is average.

Youth baseball note: FIP is less useful in youth baseball because fielding is so inconsistent. A pitcher with a 5.00 ERA might have a 3.50 FIP if their defense is bad — that pitcher is actually throwing well.

What it stands for: Fielding Percentage

Formula: (Putouts + Assists) ÷ (Putouts + Assists + Errors)

Plain English: How often a fielder makes a play when they should. A .980 fielding percentage means they make an error 2% of the time.

What's good: .990+ is elite. .980-.989 is excellent. .970-.979 is above average. .960-.969 is average.

Youth baseball note: Fielding percentage is lower in youth baseball because of inconsistent field conditions and developing skills. Don't worry about a .900 FPCT in 10U — focus on fundamentals.

What it stands for: Wins Above Replacement

Plain English: How many more wins a player is worth compared to a replacement-level player (a minor leaguer called up to fill a roster spot). It combines hitting, pitching, and fielding into one number.

What's good: 8+ is MVP level. 5-7 is All-Star level. 3-5 is above average starter. 2-3 is solid starter. 0-2 is replacement level.

Youth baseball note: WAR is an MLB stat. It doesn't apply to youth baseball. But understanding it helps you follow baseball discussions.

What it stands for: Weighted Runs Created Plus

Plain English: Measures a hitter's total offensive value, adjusted for ballpark and league. 100 is average. Above 100 is above average. Below 100 is below average.

What's good: 160+ is MVP level. 140-159 is excellent. 120-139 is above average. 100-119 is average.

Example: A wRC+ of 150 means the player creates 50% more runs than the average hitter.

Exit Velocity: The speed of the ball off the bat, measured in mph. Higher is better — 95+ mph is elite, 90-95 is excellent, 85-90 is above average.

Launch Angle: The angle the ball leaves the bat. 10-25 degrees is ideal for line drives and home runs. Below 10 degrees is ground balls. Above 25 degrees is pop-ups.

Barrel %: The percentage of batted balls with the ideal combination of exit velocity (98+ mph) and launch angle (26-30 degrees). Barrels are the best-hit balls — they produce a .500+ batting average and 1.500+ slugging percentage.

Youth baseball note: Exit velocity is becoming common in travel ball showcases. A 12U player hitting 70+ mph exit velocity is impressive. By 14U, 75+ mph is the benchmark.