I tend to think of him as an all-arounder; I was caught off guard when I looked at his steal totals since 2004: 30, 41, 36, 41,47, 17 (in 98 games), 30, 30. He's been a really reliable source of steals. During that time his success rate rounds up to 86%. We tell the story that this guy is getting old and we can expect his steals to go down, but Rollins trend line has been downward but not dramatically so. You can steal bases because you’re fast or because you know how to steal bases (or both). Rollins knows how, so age doesn’t take as much of a bite. 24 steals in a full season seems like a reasonable floor, with more on the upside.
His weakness has been batting average. He's had surprisingly low BABIP numbers. Since 2008: .290, .251, .246, .275, .262. He hits a lot of balls in the air (which is why he'll give you some homers). He plays in a good park. He's played 150+ games 9 times in his career, 140+ and 130+ once each, so he knows how to stay on the field. With his age you're hoping for 145 + replacement during one trip to the DL
My current read is that he's going 6th or 7th round in 12 team mix. If you haven't addressed SS by then, you would feel pretty good to get him there. Probably not a lot of potential to play way above that slot (i.e 1-3 round value), but a solid bet not to disappoint with a really decent floor.
He's also from Oakland, which is a mark of distinction. His mom plays in hardball women's and men's leagues and plays fastpitch softball. She swears that she’s a better player than him. Not relatively, but empirically better. She gives a funny interview.