Have played Roto for many years, so I'm a little nervous about trying a Head 2 Head type League. Will my Roto experience make the learning curve quicker? Where are the pitfalls?
I have never played in a H2H league before. But since I always try to help, I thought I'd take a look at the key differences between Roto and H2H. The point values I used for this analysis are from CBS' fantasy baseball rules. Different leagues use different point systems, so if your league uses different categories, these rules may not apply to you.
In Rotisserie you can get away with playing Stars and Scrubs. Due to the way points are accumulated in H2H, it wouldn't make nearly as much sense to carry one or two zeroes on your roster in favor of a superstar, unless you're talking about an utter stud like the 2012 versions of Miguel Cabrera, Ryan Braun, or Mike Trout. You want to make sure your line-up is as complete as possible each and every week.
While I might look at match-ups in Rotisserie, I generally wind up putting the same line-up in week in and week out. In H2H, it's common to have a nine-man line-up with a deeper reserve list. This puts more of an onus on you as an owner to mix-and-match with your line-ups. H2H owners have to be a little more attuned to lefty/righty match-ups, who is home and who is on the road, and other considerations that I wouldn't worry about quite so much in Roto.
Categorically, there is much more of an emphasis on players that produce across the board. Batting average and steals are both emphasized less, while overall slugging and on-base percentages matter more. In mixed Roto, you want B.J. Upton over Hunter Pence because of Upton's dynamic HR/SB combination. In H2H, Pence beats out Upton because all of those other counting categories add up. Take overall producers in H2H, not category monsters that don't do well across the board.
Innings matter. You still want them to be quality innings, but starting pitchers like Kris Medlen and Stephen Strasburg lose some of their value in H2H. It's easier in Roto to ride awesome ERA/WHIP guys to first place in two categories, but because of the cumulative nature of H2H you can't do this and expect to succeed. Trevor Cahill and Strasburg were comparable values in H2H, and you would have been better off with Bruce Chen in 2012 than Medlen.
Saves are deemphasized a lot. The best reliever in Roto last year was Fernando Rodney; he was the ninth best pitcher overall in mixed 5x5. In H2H, he was still the best reliever...but was only the 40th best pitcher. You would still rather have Rodney than Glen Perkins, but given the lack of comparative points, you might want to wait until the later rounds to get your relievers and not waste high picks on guys like Rodney.
If batting average is minimized for hitters, the same applies to WHIP and ERA for pitchers. In terms of the rankings, aces are aces - R.A. Dickey, Justin Verlander, Clayton Kershaw, and David Price still round out the top four - but the innings munchers like Barry Zito and Chen really get rewarded here. I still might want a top flight pitcher, but given how many points guys like Chen get just for showing up I'd be less inclined to try and build a top-flight staff and more inclined to shift my resources toward hitters and simply build a staff of consistent, durable workhorses that can give me 180-200 innings each.