The Times’ Major League Baseball rankings

Graduation season is upon us, making it a good for Times staff writer Kevin Baxter to hand out grades to Major League Baseball’s Class of 2013. (Statistics through Friday’s game. Last week’s rankings in parentheses):

HEAD OF THE CLASS

1. ST. LOUIS - MLB-best 20 wins, 2.20 ERA has rotation voted most likely to succeed (3)

2. BALTIMORE - Orioles’ bullpen (2.67 ERA, MLB-high 16 saves) getting high marks (6)

3. N.Y. YANKEES - Absences of Jeter, Rodriguez, Teixeira, Granderson don’t slow Yankees (10)

4. TEXAS - Rangers get extra credit for five-game division lead, largest in majors (2)

5. DETROIT - Failing Angels wish they had a RF like Hunter (.338) of streaking Tigers (8)

6. BOSTON - Buchholz, Ortiz deny accusations they cheated for Red Sox (1)

7. SAN FRANCISCO - Zito, Cain (2-0, 1.65 in May) push Giants into first place (7)

8. ATLANTA - Braves ace pop quiz with NL-best 49 home runs (4)

9. WASHINGTON - Bullpen gives up only one run as Nationals start month 7-1 (15)

10. ARIZONA - Goldschmidt is teacher’s pet, leads team in six offensive categories (13)

ON THE HONOR ROLL

11. CLEVELAND - Kazmir goes 2-0 with 17 Ks in two starts, Indians win 10 of 12 games (16)

12. CINCINNATI - Transfer student Choo leads majors in on-base percentage (.458) (11)

13. KANSAS CITY - Night classes sinking Royals, who are MLB-best 10-4 in day games (12)

14. PITTSBURGH - Burnett tops NL with 66 strikeouts for overachieving Pirates (5)

15. COLORADO - Altitude theory disproved with lower ERA at home than road (3.50 to 3.85) (14)

NEEDS IMPROVEMENT

16. OAKLAND - Frugal front office good with math, builds MLB’s top-scoring team on budget (9)

17. MINNESOTA - Opponents hit AL-high 301 against Twins with runners in scoring position (23)

18. MILWAUKEE - Rhodes Scholars don’t have GPAs as high as Brewers’ ERA (4.50) (17)

19. TAMPA BAY - Rays lead MLB in runs scored, third in AL in runs given up in May (18)

20. SEATTLE - Japanese exchange student Iwakuma 3-1, 1.43 in last six starts (25)

TO THE PRINCIPAL’S OFFICE

21. PHILADELPHIA - Phillies, once bullies, in bottom five in MLB in five offensive categories (19)

22. ANGELS - Prof. Scioscia’s teaching style no longer reaching his failing pupils (21)

23. N.Y. METS - Matt Harvey (4-0, 1.28), rest of rotation 4-13, 5.22 (22)

24. SAN DIEGO - Padres win league-best 11 times in last 15 games, still under .500 (28)

25. CHICAGO WHITE SOX - White Sox having trouble with the curve, batting a league-low .226 (24)

ON ACADEMIC PROBATION

26. DODGERS - Math problem: If Mark spends $230 million on team shouldn’t he win a title? (20)

27. CHICAGO CUBS - Cubs fielders — MLB-high 30 errors — need extra tutoring (27)

28. TORONTO - With nine players on DL, team’s rebuilding project gets an incomplete (26)

29. MIAMI - Marlins have scored a zero, as in runs, six times this season (30)

30. HOUSTON - Worst run differential in MLB (-75) doesn’t add up for Astros (29)