This is our fifth annual list of possible breakout players based on Spring Training statistics. We researched the value of Spring Training stats a few years back and it was quite revealing. For the most part, we agree with the common perception that they don't have value. A bad spring training means nothing. An average spring training tells us nothing. Nevertheless, we did find that when a player has an exceptional spring, it does suggest a better than a 60% chance they will take their game up a notch. It applies to teams as well. Did anybody notice the Angels are 24–8 despite losing Mark Teixeira and Francisco Rodriguez to free agency, and having three star pitchers hurt in John Lackey, Ervin Santana, and Kelvim Escobar?
We define "exceptional spring" as a positive difference between a hitter's spring training slugging percentage and their lifetime slugging percentage of 200 points or more.
We analyzed hitters with both a minimum of 200 career regular season at–bats and with a minimum of 40 spring training or World Baseball Classic at–bats (through spring training games of Thursday, April 2) and found the following 46 players.
| Possible Breakout Players |
| (Slugging percentage 200+ points better in spring training) |
| Hitter | Diff. | Spring | Career |
| Mark Teahen, Royals | .494 | .915 | .421 |
| Erick Aybar, Angels | .436 | .784 | .348 |
| Milton Bradley, Cubs | .429 | .886 | .457 |
| Jeff Mathis, Angels | .388 | .714 | .326 |
| John Buck, Royals | .358 | .756 | .398 |
| J.J. Hardy, Brewers | .351 | .797 | .446 |
| Juan Castro, Dodgers | .329 | .660 | .331 |
| Endy Chavez, Mariners | .322 | .691 | .369 |
| Mark DeRosa, Indians | .313 | .735 | .422 |
| Corey Hart, Brewers | .312 | .797 | .485 |
| Torii Hunter, Angels | .309 | .778 | .468 |
| Koyie Hill, Cubs | .287 | .569 | .281 |
| Miguel Olivo, Royals | .285 | .696 | .411 |
| Jason Lane, Blue Jays | .279 | .736 | .457 |
| Alex Gordon, Royals | .265 | .686 | .421 |
| Chris Shelton, Mariners | .259 | .720 | .461 |
| Nelson Cruz, Rangers | .258 | .689 | .431 |
| Jolbert Cabrera, Orioles | .257 | .622 | .365 |
| Kendry Morales, Angels | .254 | .663 | .408 |
| Robb Quinlan, Angels | .251 | .667 | .416 |
| Chris Woodward, Phillies | .250 | .625 | .375 |
| Ivan Rodriguez, Astros | .246 | .721 | .475 |
| Ryan Spilborghs, Rockies | .239 | .705 | .466 |
| Carlos Ruiz, Phillies | .236 | .595 | .359 |
| Jed Lowrie, Red Sox | .235 | .635 | .400 |
| Russell Martin, Dodgers | .234 | .667 | .433 |
| Josh Fields, White Sox | .233 | .688 | .454 |
| Craig Monroe, Pirates | .233 | .676 | .444 |
| Angel Berroa, Yankees | .232 | .610 | .378 |
| Yuniesky Betancourt, Mariners | .231 | .632 | .400 |
| Doug Mientkiewicz, Dodgers | .229 | .634 | .405 |
| Craig Counsell, Brewers | .224 | .568 | .344 |
| Jose Lopez, Mariners | .221 | .619 | .398 |
| Ian Stewart, Rockies | .218 | .661 | .443 |
| Josh Hamilton, Rangers | .215 | .753 | .538 |
| Carlos Delgado, Mets | .215 | .761 | .546 |
| Jimmy Rollins, Phillies | .214 | .655 | .441 |
| Jayson Werth, Phillies | .211 | .662 | .451 |
| Adrian Gonzalez, Padres | .209 | .703 | .494 |
| Andy LaRoche, Pirates | .208 | .480 | .272 |
| Fred Lewis, Giants | .208 | .642 | .434 |
| Eric Bruntlett, Phillies | .204 | .548 | .344 |
| Carlos Gomez, Twins | .203 | .554 | .350 |
| Brandon Inge, Tigers | .202 | .593 | .392 |
| Russell Branyan, Mariners | .200 | .685 | .485 |
| Mark Teixeira, Yankees | .200 | .741 | .541 |
(minimum 200 career AB and 40 spring Training or WBC AB thru April 2, 2009)