2012 projection: 131 games, .271 BA, .364 OBP, .537 SLG, 31 HR, 83 RBI
2012: 108 games, .227 BA, .343 OBP, .469 SLG, 24 HR, 56 RBI
2013 projection: 127 games, .248 BA, .350 OBP, .498 SLG, 29 HR, 75 RBI
2013: 139 games, .259 BA, .360 OBP, .482 SLG, 23 HR, 92 RBI
2014 projection: 137 games, .246 BA, .348 OBP, .471 SLG, 26 HR, 79 RBI
2014: 119 games, .248 BA, .370 OBP, .419 SLG, 17 HR, 55 RBI
2015 projection: 135 games, .246 BA, .355 OBP, .453 SLG, 23 HR, 72 RBI
The biggest discrepancy between Mike Napoli's 2013 season and his 2014 season is in the power numbers, primarily home runs and RBIs. Of course, there were fewer Red Sox on base for Nap to drive in this season than last, and he played twenty fewer games this season than last, all well dealing with assorted injuries.
Napoli is currently recovering from surgery to relieve his sleep apnea, a condition that restricts airways during sleep, causing loud snoring and a disruption in breathing. Sleep apnea sufferers often feel tired even after a full night's sleep, so if the surgery was successful it stands to reason Napoli will be better rested in 2015.
After last year's World Series, the Red Sox extended Nap to the tune of two years, and $32 million, so he's due $16 million in 2015, and will be a free agent at the conclusion of next season. If Napoli can perform up to Bill James' projections for him next season, it will be money well spent.
Mike Napoli has embraced the Red Sox and Boston in a way that few players can, and his current contract is exactly the kind of thing the team should pursue in the future: short in years, and perhaps a bit generous in annual value.