Baseball Fielding Percentage Calculator

182 putouts, 371 assists and 16 errors make a .972 fielding percentage

Fielding percentage is the share of a fielder's chances that are handled without an error. Official Baseball Rule 9.21(d) says to divide the sum of putouts and assists by the sum of putouts, assists and errors, and it calls that denominator chances. A shortstop with 182 putouts, 371 assists and 16 errors has 569 chances, and (182 + 371) ÷ 569 = .972. Baseball writes ratios below 1 without the leading zero, so it is .972, not 0.972.

That .972 is .001 below the 2026 MLB shortstop league average of .973. Of the 19 qualified MLB shortstops, 11 were higher. If the same .972 belonged to a first baseman, it would be far below the MLB first-base average of .994. Because the bar differs this much by position, the calculator above has you pick a position on the defense map first and compares you with that position's league average and qualified players. The grid below converts the same line to 100 chances to show how many boxes are errors, and the plane adds the range that fielding percentage cannot capture.

How to use the calculator

1. Choose the league to compare with (KBO or MLB). The numbers on the defense map switch to that league's 2026 regular-season average fielding percentage by position.
2. Tap a position on the defense map. If a player played several positions, enter each position separately, as record sites list them.
3. Enter putouts, assists and errors. The fielding percentage, the 100-chance grid and sentences comparing you with the league average and the qualified players appear at once.
4. Add innings played (written as the scoresheet does, like 1094.1) or games, and a dot appears on the plane along with the range factor (RF/9 and RF/G).
5. Enter a target fielding percentage, or press the "League avg" or "Top qualified" button, to see how many more plays without an error it takes to reach it.

How it is calculated

• Fielding percentage: (putouts + assists) ÷ (putouts + assists + errors), rounded to three decimals. If there is at least one error but the rounded value would be 1.000 (1 error in 2,000 chances = .9995), it is not shown as 1.000 and gets four decimals instead.
• Putout (PO): credited to the fielder who puts out a batter or runner directly (Rule 9.09). Catching a fly ball, taking a throw and touching a base, or tagging a runner is a putout, and a strikeout is a putout for the catcher.
• Assist (A): credited to a fielder who helps make an out (Rule 9.10). A shortstop who fields a grounder and throws to first is the classic case, and one fielder gets only one assist on a play.
• Error (E): a fielder's mistake that helps the offense (Rule 9.12). The official scorer decides, and mental mistakes such as poor judgment, or a ball handled late without a misplay, are not charged as errors.
• Range factor: RF/9 = 9 × (putouts + assists) ÷ innings played, and RF/G = (putouts + assists) ÷ games. The .1 and .2 in innings mean 1 and 2 outs, so 1094.1 innings is calculated as 1094⅓.
• Error-free plays to reach a target: the smallest n for which the displayed fielding percentage, (putouts + assists + n) ÷ (chances + n) rounded to three decimals, reaches the target. This is the same basis as the verdict sentence, so a figure that rounds to .965 counts as reaching a .965 league average. If you are already past the target, it shows the largest number of additional errors, with no other plays, that still keeps you at or above it.
• League average: the putouts, assists and errors of every player at that position added together, then divided. It is not a simple average of each player's fielding percentage.

MLB's glossary abbreviates fielding percentage as FPCT and defines total chances (TC) as putouts + assists + errors. Some older articles and tools call putouts and assists by other names, but the records are the same.

League average fielding percentage by position (2026 regular season)

Catchers and first basemen are above .99, while shortstops and third basemen stay between .95 and .97. Pitchers were lowest in both leagues, with more than 5 errors per 100 chances. Only KBO catchers had a higher fielding percentage than their MLB counterparts; the other 8 positions were all lower than in MLB. The widest gap was at third base, with 4.9 errors per 100 chances in the KBO and 3.9 in MLB.

The KBO values add up the 890 player fielding rows on the KBO record room by position, and the totals match the team fielding records (38,282 putouts, 13,412 assists, 969 errors). The MLB values add up 2,748 player fielding rows from the MLB Stats API and match the 30-team totals (129,239 putouts, 40,570 assists, 2,499 errors). Designated hitters have no fielding records, so they are left out.

Why compare with qualified players

The league average includes backups who played only a few games. To see where a regular stands, it is more accurate to compare with players who met the qualifying standard. This calculator uses the fielding-title qualifier from Official Baseball Rule 9.22(c). A catcher must play at least half of the team's scheduled games at the position, an infielder or outfielder at least two-thirds, and a pitcher must throw at least as many innings as the team has scheduled games. In the 144-game KBO that is 72 games for catchers, 96 for other fielders and 144 innings for pitchers. In 162-game MLB it is 81, 108 and 162 innings. The qualified list on the MLB official stats matched this standard exactly.

The KBO Defense Award (created in 2023) uses different candidate standards. Infielders and outfielders must have played at least 720 innings at the position, which is the team's games multiplied by 5 innings, and pitchers need at least 48 innings. Rule 9.22 counts a game as a game even if the player came in as a substitute, while the award counts innings, so the two can disagree. Kwon Dong Jin (KT), the 2026 KBO shortstop leader in fielding percentage, played 112 games at shortstop and met the 9.22 standard, but his 602 innings fell short of the award standard.

The fewer the chances, the heavier one error

One error moves fielding percentage by roughly 1 ÷ chances. Every row in the table below has a 2% error rate (.980). With 50 chances, one error drops it by .019, but with 1,200 chances it drops by only .001.

The last column is how many more error-free plays it takes until the rounded figure shows .990, a little over 90% of the chances so far. To reach exactly .990, cutting the error rate in half from 2% to 1%, you need as many more error-free chances as you have had so far. When a season brings only a few dozen chances, as in rec-league ball, one error can move fielding percentage by almost .02, so look at the "One error more or fewer" row of the calculator too.

What fielding percentage misses: range

Fielding percentage counts only balls a fielder gets to. A ball he cannot reach and that falls for a hit is neither an error nor a chance, so a fielder who avoids hard plays can end up with a higher fielding percentage. In a 1976 piece in Baseball Digest, Bill James suggested looking at plays made per game instead, and that became range factor. MLB's glossary notes that the per-nine-innings version (RF/9) is now more widely used.

Among the 19 qualified MLB center fielders in 2026, Henry Bolte had the lowest fielding percentage (.981) and the highest RF/9 (3.10), while Justin Crawford, third in fielding percentage (.996), had the lowest RF/9 (2.03). In the KBO, by contrast, Park Hae Min (LG) was first among the 6 qualified center fielders in both measures, with a 1.000 fielding percentage and a 2.95 RF/9. The higher up and to the right a player sits on the plane, the fewer errors he makes and the more plays he makes.

Range factor is not perfect either. An infielder behind a pitching staff that gets many ground balls has more chances to make plays, and behind a staff that strikes out many batters he has fewer. MLB also publishes Statcast Outs Above Average (OAA), which calculates the catch probability of each batted ball and counts how many more outs a fielder made. It needs batted-ball tracking data, so it cannot be calculated from public box-score records.

Common mistakes

• Combining records from several positions: adding a third baseman's line to a shortstop's line gives a value between the two position averages and ruins the comparison. Calculate each position separately.
• A 1.000 on few chances: 34 chances with no errors is 1.000, but a single error drops it to .971. Look at the number of chances before the 1.000.
• Judging a catcher's defense by fielding percentage: most of a catcher's putouts come from strikeouts, so more strikeouts by the staff raise it. Passed balls and framing are not part of fielding percentage, and a runner caught stealing counts only as the catcher's assist, not as a rate.
• RF/G from games: a game counts as one even if the player fielded only one inning as a substitute, so a player who often comes in mid-game gets a low RF/G. If you know the innings, use RF/9.
• Comparing team and individual fielding percentage: a team's fielding percentage uses the same formula on the team's total putouts, assists and errors. In the 2026 regular season, team fielding percentage ranged from .979 (NC, Hanwha) to .984 (Samsung, KT, SSG) in the KBO and from .982 (Nationals, Giants) to .990 (Cubs) in MLB, and the whole-league figures were .982 for the KBO and .985 for MLB. Compare a team record with the whole-league figure, not with a position average.

Limits

• Errors are the official scorer's judgment, so the same play can be an error with one scorer and a hit with another.
• Fielding percentage and range factor do not directly measure range, arm or positioning. Batted-ball tracking measures such as OAA cannot be calculated from public records, so they are not included.
• The leagues to compare with are the KBO and MLB. League averages and qualified players are the final 2026 regular-season records, and the postseason is not included.
• Qualified players are picked by the games and innings thresholds of Rule 9.22(c); the pitcher exception, which can crown a pitcher with fewer innings but more chances, is not applied. A few names may differ from the KBO Defense Award candidate list.
• What you enter is not sent to a server; it is calculated inside this browser. Values go into the address only when you press Copy link or edit a value.

As of The formulas and definitions were checked on 2026-10-22 against the 2026 Official Baseball Rules and the MLB glossary. League averages and qualified players were calculated the same day from the 2026 regular-season records of the KBO record room and the MLB Stats API.

Sources

• 01Official Baseball Rules 2026 (MLB)9.09 putouts, 9.10 assists, 9.12 errors, 9.21(d) fielding average and chances, 9.22(c) fielding title qualifier
• 02MLB Glossary: Fielding Percentage (FPCT)Putouts plus assists divided by total chances (putouts, assists, errors)
• 03MLB Glossary: Total ChancesChances = assists + putouts + errors, mainly used as the denominator of fielding percentage
• 04MLB Glossary: Error (E)When the scorer judges that a fielder missed an out an average fielder would have made
• 05MLB Glossary: Range Factor (RF)(Putouts + assists) divided by games played in the field, the per-nine-innings version is now more common, created by Bill James
• 06SABR: 50 at 50: AnalyticsRange Factor (1976): Bill James, Baseball Digest, March 1976, "Fielding Statistics Do Make Sense!"
• 07MLB Glossary: Outs Above Average (OAA)A range measure calculated from batted-ball tracking
• 08KBO record room: player fielding2026 regular season: 890 rows of games, innings, putouts, assists and errors by position
• 09KBO record room: team fielding2026 regular season, 10 teams: 38,282 putouts, 13,412 assists, 969 errors
• 10KBO: Defense AwardCreated in 2023, candidate standards: pitchers 48 innings, catchers 72 games, infielders and outfielders 720 innings
• 11MLB Stats API: 2026 player fieldingRegular season, 2,748 rows by position; 30-team totals 129,239 putouts, 40,570 assists, 2,499 errors; qualified players via playerPool=qualified

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