Here’s Major League Baseball rule 10.22(a), which I’m told is the former rule 10.23(a):

10.22 Minimum Standards For Individual Championships

To assure uniformity in establishing the batting, pitching and fielding championships of professional leagues, such champions shall meet the following minimum performance standards:(a) The individual batting, slugging or on-base percentage champion shall be the player with the highest batting average, slugging percentage or on-base percentage, as the case may be, provided the player is credited with as many or more total appearances at the plate in league championship games as the number of games scheduled for each club in his club’s league that season, multiplied by 3.1 in the case of a Major League player and by 2.7 in the case of a National Association player. Total appearances at the plate shall include official times at bat, plus bases on balls, times hit by pitcher, sacrifice hits, sacrifice flies and times awarded first base because of interference or obstruction. Notwithstanding the foregoing requirement of minimum appearances at the plate, any player with fewer than the required number of plate appearances whose average would be the highest, if he were charged with the required number of plate appearances shall be awarded the batting, slugging or on-base percentage championship, as the case may be.

Pretty simple stuff, really. If a player is short the required number of plate appearances to qualify, you just give him an 0-for-x until he has enough, and if then he’s still in front, he wins.

It’s rarely used in the major leagues. It did give Tony Gwynn a batting title in 1996, and it also allowed Barry Bonds to lead the National League on on-base percentage last year, but it hasn’t altered the slugging title since 1954, when Ted Williams qualified this way.

The rule’s use in the minors is a far more common practice, as players (especially those who are doing particularly well) tend to move out of leagues as they advance through a system, leaving many players with outstanding numbers falling a little short of the qualification minimums. In the course of doing an outstanding job as the official statistician of minor league baseball, MLBAM just released their revised leaders now that rule 10.22(a) has been applied. While we have no changes in any batting titles this year, the slugging percentage leader has changed in four of the ten full-season leagues:

Triple-A International League

Leader at the end of the year: Mike Hessman, Toledo (Tigers): .540
Adjusted Leader: Shelley Duncan, Scranton-Wilkes Barre (Yankess): .577

Hessman is a 29-year-old career grinder who has now slugged 254 home runs in the minors. He got his second callup by the Tigers when the season ended, and he’s doing what he does best: hitting home runs (three in 41 at-bats), and striking out a lot (14). Duncan got called up in late July, but with 387 plate appearances, he was just one short of qualifying, so the 0-for-1 added to his line dropped his slugging just .001 to .576, making him an easy champion, mostly thanks to 25 home runs in 336 at-bats. Duncan got a lot of attention for hitting five home runs in his first seven games with the Yankees, but he’s fallen into the shadows of Joba Chamberlain and Ian Kennedy of late, and in his last 18 games he’s come down to earth by going 8-for-34 (.235) with just one homer.

Double-A Eastern League

Leader at the end of the year: Greg Jacobs, Reading (Phillies): .539
Adjusted Leader: Luis Jimenez, Bowie (Orioles) .591

A former Seattle prospect, Jacobs had an outstanding year with the R-Phils, hitting .310/.377/.539 with just 64 strikeouts, but he’s also a player in his 30s who is simply filling up a roster spot. Jimenez is the definition of journeyman, yet he’s only 25. Originally signed by the Athletics–who released him after his 2001 stateside debut due to some makeup issues–Jimenez has already excited Baltimore fans once, as he put up a .375/.474/.597 line in the Appy league in 2002. He was injured the next year, and has spent the last three years toiling away in the Dodgers, Twins, and Red Sox systems. The Red Sox let him go after he hit .148/.231/.210 for Triple-A Pawtucket, and he found himself back in the Eastern League and back in the Orioles organization, where he hit .366 with 15 home runs in his last 50 games. He fell 17 plate appearances short of qualifying, and even adding that imaginary 0-for-17 mark to his line, he still overcame Jacobs with a .561 mark. It was an outstanding year, but he’s not much of a prospect.

Double-A Southern League

Leader at the end of the year: Evan Longoria, Montgomery (Devil Rays): .528
Adjusted Leader: Charlton Jimerson, West Tenn (Mariners): .565

Longoria won Southern League MVP honors, and it was well-deserved, as one of the top prospects in baseball finished among the league leaders in numerous offensive categories despite playing in just 105 games prior to a Triple-A promotion. That said, you have to root for Jimerson. Coming from a sad and troubled background, Jimerson ended up attending the University of Miami on an academic scholarship, and rarely played for the Hurricanes until the 2001 College World Series, where he earned Most Outstanding Player honors. He played six years in the Houston system, marked mostly by his incredible athleticism and horrible approach; per 162 games, he averaged 40 walks and 213 strikeouts. He set a new career high this year with 23 home runs in just 322 Texas League at-bats, and two more in the Pacific Coast League, and he’s now in the big leagues for September. Just 17 plate appearances short of qualifying, his 0-for-17 addition still puts him at .537, good enough to clinch the title. Jimerson is a great story, but on baseball terms alone, he’s most similar to Reggie Abercrombie in the sense that his baseball skills just didn’t catch up to the tools fast enough.

High-A Carolina League

Leader at the end of the year: Micah Schnurstein, Winston-Salem (White Sox): .508
Adjusted Leader: Kala Kaaihue, Myrtle Beach (Braves): .583

Schnurstein is the definition of an organizational player, sputtering away at High-A in his sixth professional season. Kaaihue was a much different story, and his prospect status has basically been on a roller coaster ride over the past two seasons. Signed by Atlanta as an undrafted free agent in 2005, Kaaihue led the organization with 28 home runs last year, and he looked like he was proving it was for real with a monster line of .298/.410/.583 at Myrtle Beach this year by bopping 22 home runs and drawing 53 walks in just 89 games. Just two plate appearances short of qualifying, he easily crushes Schnurstein for the title. Unfortunately, Kaaihue’s performance following a promotion to Double-A was nothing short of a disaster–not only did he go homerless in 118 at-bats while striking out 51 times, but he compiled just 15 hits, putting up a .127/.211/.186 line, a performance at the plate that even a pitcher would be embarrassed by.

In addition to the slugging adjustments, there were two changes made to the on-base percentage leaders.

High A Carolina League

Leader at the end of the year: Brett Bigler, Wilmington (Royals): .399
Adjusted Leader: Kala Kaaihue, Myrtle Beach (Braves): .410

We’ve already gone over Kaaihue. Bigler was a seventh-round pick last year out of UC Riverside, and while almost leading a High-A league in on-base percentage in a full-season debut might look like a big accomplishment, Bigler isn’t much of a prospect. He’s a good center fielder with speed who knows how to draw walks (74 in 328 at-bats), but his overall line of .259/.399/.311 tells you the whole story–he can draw walks, yes, but he can’t hit.

Short-Season Northwest League

Leader at the end of the year: J.D. Pruitt, Vancouver (Athletics): .460
Adjusted Leader: Josh Donaldson, Boise (Cubs): .470

Pruitt was a 21st-round pick this June out of tiny Montevallo College in Alabama, and he set a school record with a .535 on-base percentage this year. While he’s not much of a prospect, his numbers were still pretty remarkable as a statistical anomaly. In 61 games, Pruitt drew 50 walks in 180 at-bats, while also striking out 64 times. The most remarkable thing is that he led the minor leagues by getting hit by 34 pitches. He was plunked twice in a game six times, and had four streaks of three or more games in which he got plunked, including one remarkable seven-game stretch in mid-July in which he got hit in seven straight contests. Donaldson had a breakout year at the plate this season at Auburn, and if he can stay behind the plate (the athleticism is there, the experience is not) he could be a steal with the 48th overall pick in the draft. Donaldson absolutely mashed at Boise, delivering a .346/.470/.605 line; he’ll rank high on the Cubs’ offseason Top 10 prospects list.