A few things about this: 1. It's a fascinating idea and I've always wondered if it would really work. I've even considered a 13 man 'rotation' where you have four guys a game - basically get them try and limit them to only having to go through the rotation once a game. You have a 13th guy for mop up action, extra innings, etc. If a guy pitches every third game, that's 54 games. Say they average 2.1 IP, that's 126 IP in a season. 2. I think the time someone would try it in its purest form would be an expansion team. No star pitchers - just a bunch of mediocre guys who are happy for a gig. 3. As noted, the plan goes awry when you have really good pitchers. I mean, you got Clayton Kershaw so you want the guy out there 250 innings. Perhaps you could build a hybrid system to accommodate players like Kershaw. Let them pitch their 6-7 innings - that sort of thing. 4. Regarding your 'extra' man. Ideally you get a knuckleball guy. Have someone that could throw 5 inning back-to-back-back without any issue. The guy might not be that good - but he could clean up blow out games, and go deep into extra innings if needed. Just a thought. 5. The system would eliminate 'match up' pitching (for the most part). You might regret the flexibility of bringing in a player to face one or two batters - that sort of thing. 6. One interesting thing to committing to a plan like this is that you don't over pay for pitchers. You're not drafting them with your high picks, you're not giving them $25M a year contracts. That means you could really focus on drafting and developing hitters. At least, theoretically. 7. Teams are always looking for advantages. Let's be honest - the cost of young starting pitching can be enormous. With this system, you can find those guys who don't quite cut it as 6 inning starters - or wipe out relievers - and acquire them - likely at a far lower cost than other pitching prospects. I would love to see someone try this. As I said, I think an expansion team would offer a great opportunity to give it whirl. The other situation I would love to see it happen is with a club with really bad pitching - and a bad farm system. I'm thinking the LA Angels. Their major league staff is pretty awful, and their minor league system is pretty bare. So why not give something like this a chance.