September 13, 2011

Baseball Prospectus News

Announcing Integration of Minor-League Statistics

by Rob McQuown

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The minor-league regular seasons may be done, but the analysis of minor-league statistics has just begun. Observant readers have already noticed that various pages at Baseball Prospectus have started including minor-league stats with all the same depth of statistics for which Baseball Prospectus is known. For example, the “Batter Season—Standard” report shows the top-15 Triple-A leaders in BWARP:

You’ll find the usual statistics here, but that’s not all. For example, the seasonal batting report contains—by default—the average OPS of opposition pitchers faced (OPP_QUAL_OPS) and the personal Batter Park Factor (BPF). These stats involve analysis of every single plate appearance made by an individual player, making them much more accurate than general season-level stats. And, as always, subscribers can tailor reports to their liking by clicking on Statistic Selection and adding or removing columns as desired. Any report can be bookmarked at any time, as a unique URL is generated for each custom report. For instance, this report is:

http://www.baseballprospectus.com/sortable/index.php?cid=1049525

Clicking on the Triple-A Batting WARP leader's name, the Cardinals' 2009 13th-round pick Matt Carpenter, brings up his player card. His pre-season PECOTA gave some indication that he might be able to help a team, though only marginally (.259 TAv, not bad for a position—third base—with an average batting line of .252/.316/.386). Carpenter’s pre-season PECOTA appears on the top of the player cards all season long, as he isn't expected to start games for the Cardinals and thus hasn't been entered into the depth charts. More active players have their Rest-of-season PECOTA displayed. But the important new information on the player card page is the minor-league statline for 2011, in the “Recent Performance” table (second on the page):

All levels of play are included, as can be seen with Jose Altuve, one of the few bright spots on the Houston Astros:

Of course, the leaderboards aren't just for hitters. If, for example, someone wanted to find the FRA leaders in Double-A this year (50 or more innings pitched), that's easily done (see following graphic). And, of course, the same tailored stats (PPF for Pitcher Park Factor) and OPP_QUAL_OPS (opponent batters average OPS) are available to subscribers, by clicking on “Statistic Selection.”

The flexibility doesn't end there. For subscribers who have set up teams in Team Tracker, these players can be listed on the Sortables reports, intermixed freely with major-league players. This author plays in a very realistic Strat-O-Matic league with 30 teams with 150-player rosters (with 40-man roster rules like MLB, Rule 4 draft, Rule 5 draft, salaries, free-agent bidding, etc.) Since that roster has been entered into Team Tracker (under USBL, the acronym for the league), the Triple-A batting and pitching stats can be easily displayed in the Sortables reports by choosing USBL from “My Team Tracker Teams.” For batters, only the players officially on the team (not including the players in the “WATCHED” section) are included:

For pitchers, the same USBL roster is used, but the list is expanded to include watched players:

Of course, thinking about simulation baseball (such as Strat-O-Matic) leads naturally into the question of left/right splits. Not that batters always sustain their splits as they progress levels, but it's still tempting to look at the best batters against right-handed pitching, for example. The following table includes the current leaders in On-base Plus Slugging (OPS) against right-handed pitching from High-A, for example (100 or more PA):

One question that is often raised about minor-league statistics and should be addressed here is that of some form of major-league equivalents or translations (formerly “Davenport Translations”). Our MLEs are based on a subset of the PECOTA logic, and we’re still testing the entire system. As our series of new feature announcements continues, we expect to be able to release our MLEs soon.

We hope you will enjoy perusing the mountains of minor-league statistics now available and that you have been reminded of some of the features on the Sortable Reports, which allow almost unlimited flexibility in stat-seeking and analysis. As always, suggestions are welcome—feel free to email me or Customer Service, or to add comments here. We read them all and do our best to incorporate as many as possible.

Rob McQuown is an author of Baseball Prospectus. Follow @robmcquown
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