Jered Weaver has started out this season on quite a roll, posting a 6-0 record with a sparkling 0.99 ERA - along with his 1.6 fWAR, those are best in the majors. On the heels of his excellent 2010, Weaver has established himself as one of the best young pitchers in the game. What does such a start portend for the full season though? I thought it might be fun to look at how April's top pitchers from the past few seasons finished the year (mainly using fWAR).
Roy Halladay led the way with 1.5 fWAR (4-1, 1.80 ERA, 2.30 FIP, 2.48 xFIP), with Tim Lincecum (1.4 fWAR) and Ubaldo Jimenez (1.2 fWAR) close behind. All three regressed slightly - Timmy the most, though he also had the lowest FIP/xFIP (1.97/2.10) at the time - but they all finished in the top 12 in end of year fWAR. Jimenez was #5, while Doc placed 2nd (behind Cliff Lee) and, of course, won the Cy Young award.
This was the one year were April's top pitcher still ketp that crown at the end of the season, as Zack Greinke had that great start (5-0, 0.50 ERA, 1.40 FIP, 2.42 xFIP) which led to his great Cy Young season (#1 fWAR of 9.4). Javier Vazquez started out second (1.5 fWAR) and ended up seventh (6.5 fWAR). Tim Lincecum started out third (1.4 fWAR) and ended up also third (8.4 fWAR).
Cliff Lee was #1 at 1.7 fWAR (5-0, 0.96 ERA, 1.94 FIP, 2.96 xFIP), and ended up seventh at 7.2 fWAR. Javvy had the second highest April fWAR for the two years in a row, but in '08 he fell all the way to 17th (with a still good 4.9 fWAR). Brandon Webb was third, and dropped to sixth (6.0 fWAR). CC Sabathia's 7.6 fWAR was tops in the majors this year, but he did that split between the two leagues and walked away with no hardware.
Roy Halladay with his second leading April (well, first, chronologically) - 1.4 fWAR, 4-0, 2,28 ERA ,3.11 FIP, 3.32 xFIP - but both Jake Peavy (1.4 fWAR, 3-1, 2.06 ERA, 2.30 FIP, 3.08 xFIP) and Ted Lilly (!) (1.4 fWAR, 2-2, 2.18 ERA, 2.18 FIP, 3.31 xFIP) were right there as well. They finished sixth, fourth, and (not surprisingly) 33rd. Peavy ended up with the NL Cy Young, and Roy Halladay ended up a smidgen behind one of his current team-mates in fWAR (ahem... Joe Blanton).
This was probably the most mediocre overall year I looked at, as Curt Schilling, Kevin Millwood, and Mike Mussina ended up 8th, 13th, and 11th, respectively in fWAR (all in the 5.1-5.5 range). The lowest season ERA of the three was Mussina's 3.51.
Pedro Martinez (1.9 fWAR) was only 2-1 with a 2.75 ERA, but his 1.33 FIP was the lowest of any of the top starters for any year here. He finished eighth in final fWAR at 5.9. It was April's #2 man, Johan Santana, that was tops in the end (7.6 fWAR). Though he won the Cy Young in both 2004 and 2006, in '05 it was Bartolo Colon (16th with 4.5 fWAR) and his 21 wins that got the honor. Random 2005 April FIP note: FanGraphs has Fransisco Rodriguez with a -0.08 mark for the first month (13.9 K/9, no walks, no home runs) - that's pretty sick, even if it is only 10.1 IP.
I looked at 2002-2004 too, but I think this is a fine stopping point (will post those in the comments if anyone wants). The average fWAR final ranking for the April leader was 4.8, with the second place guy coming in at 9 and the third place guy at 13.8. Not too unexpected. This neither means that Weaver is going to fall off as the season goes on (I mean, he will at base, but perhaps not relative to his peers), nor that he's a lock for the Cy Young.