Its an interesting strategy. I was a little skeptical of the assumption that a lousy group of starters like ours gets through 5 IP every day, esp. only facing lineups twice. Because as it is, with a 5 man rotation and 100 pitch count limit, the 2013 Twins starting staff is averaging less than 5.2 IP per start. I pulled some stats. These include 3rd and 4th time through the order, so they are a little skewed, but as a staff, the Pitches per PA and Whip are this [TABLE=width: 200] PPA WHIP 3.814 1.522 [/TABLE] That's 4.522 batters per inning, and 17.25 pitches per inning on average. If you take them out after 2 trips through the order, that would only equate to roughly 4 innings. If you change the criteria to Pitch count, instead of trips through the lineup, you see this:
Split BA OBP SLG OPS
Pitch 1-25 .258 .314 .395 .708
Pitch 26-50 .292 .338 .438 .775
Pitch 51-75 .274 .342 .424 .765
Pitch 76-100 .318 .374 .490 .864
Pitch 101+ .328 .418 .517 .935
Provided by Baseball-Reference.com: View Original Table
Generated 9/7/2013. Not surprisingly, the same problem shows up. it would require over 86 pitches to get through 5, on average. That's 11 pitches or so too many. So, realistically, you'd be asking your bullpen to complete innings 5-9. A 6 inning guaranteed workload on 9 guys. Sounds taxing, but maybe it could be done. See the days rest splits:
Split PA BA OBP SLG OPS
0 DaysGR 247 .235 .313 .304 .617
1 DayGR 607 .227 .299 .345 .644
2 DaysGR 437 .222 .282 .365 .647
3 DaysGR 365 .269 .316 .424 .740
4 DaysGR 155 .210 .265 .343 .607
5 DaysGR 39 .237 .256 .421 .677
6+ DaysGR 128 .231 .278 .274 .551
Provided by Baseball-Reference.com: View Original Table
Generated 9/7/2013. Probably skewed a little because the guys pitching back to back are limited to the back end guys (Fien, Burton, Perkins). We really don't know much (or I don't know much) about optimal rest days and pitch counts for relievers. If you can get away with throwing these guys 4-6 days a week, for 15-25 pitch stints, then it would be a very intriguing strategy. I'm a little dubious about the ability to get through that kind of guaranteed workload over the course of a season though.