Knowing that you have a scoring category locked down is a great feeling when playing in a roto league. This is a feeling that doesn't exactly translate into head-to-head leagues all that well being that every week is a blank slate. Does this mean that players that do only one or two things really well are not valuable or useless in head-to-head leagues? Absolutely not. However, it does change their value when compared to players who do multiple things well.
One guy who does one thing extremely well is Carl Crawford. Crawford is great on the basepaths which shows in his stolen base and run totals. An argument can be made that Crawford is the most valuable outfielder to own in roto leagues. So lets compare him to another top outfielder Matt Holliday.
Carl Crawford: .307/19/90/110/47
Matt Holliday: .312/28/103/95/9
While Holliday, ADP 22.41, definitely holds his own in this comparison, I would take Crawford, ADP 15.59, in a 5x5 roto league every time given his huge advantage in stolen bases. Holliday is the better power hitter and his spot in the batting order provides him with great RBI potential, yet Crawford is able to put enough stats up in those categories that his shear dominance in swiping bases makes him more valuable as a roto outfielder. Now lets look at what happens when we look at these two players through the eyes of a head-to-head player.
Carl Crawford: .307/19/90/110/47/46/104/.356/.495
Matt Holliday: .312/28/103/95/9/69/93/.390/.532
These category additions are not very helpful to Crawford. You can call strikeouts a push, but Holliday takes all of the new categories which pushes him ahead of Crawford in head-to-head leagues. Some head-to-head leagues also use doubles and triples as additional categories. If this is the case Crawford takes on some additional value as triples are more rare, yet Holliday remains the better pick as his lead in doubles (ensured by Crawford converting many of his into triples) negates some of this benefit.
Ultimately you can not go wrong with either of these players as they are both huge contributors. Depending on your strategy they may have different appeal to you which is why I would like to leave you with one last point. Much of Crawford's value is based on his ability to steal bases. If you look at the last few years he has gone through periods where many of those steals have come in bunches. In 2010, 22 of his steals came in June and July combined while Crawford only stole 3 in all of August. Then in 2009, Crawford stole over half of his 60 bases in May and June. This streaky tendency is discouraged by the weekly nature of head-to-head style fantasy baseball. Keep this in mind.