How much new information do you need before you can change your opinion on a player? In the case of Ubaldo Jimenez, you've got four mostly mediocre seasons in a row in his recent past, four starts worth of improvement to go on. Is that enough to buy in?

First, let's look at just how Jimenez has managed to improve. If we were looking at 22 innings with the same peripherals as last season's forgettable 4.81 ERA campaign, it would be a lot easier to dismiss Jimenez. However, he has improved his strikeout rate, walk rate and groundball rate, the latter two of which he has improved dramatically.

Jimenez has cut his walk rate from 5.53 per nine to 3.18, but it isn't like he is working in the strike zone significantly more often. He has thrown 48.6 percent of his pitches in the zone, per PITCHf/x; up from last year's 47.9 percent mark, but down from his career 49.4 percent mark.

So, what gives? It turns out, after 1,400 erratic innings, Jimenez's reputation simply precedes him. Opposing hitters are swinging at just 34.7 percent of Jimenez's pitchers, a lower rate than ever before. While that might be paradoxical with a lower walk rate, the fact that hitters are swinging at just 51.2 percent of his pitches in the strike zone means we're seeing a lot more called strikes than ever before.

Opposing batters aren't offering at anything Jimenez is throwing, which makes his lower walk rate more impressive, but also means the strikeout rate might have nowhere to go but down. If hitters start attacking Jimenez' in-zone pitches more aggressively, the strikeout rate and walk rate are likely to go in opposite directions.

This might not be such a big concern if Jimenez still had elite swing-and-miss stuff, but with his velocity dropping another tick, he is missing fewer bats than ever. His 6.1 swinging strike rate suggests that his 8.7 K/9 is being held up by an awful lot of called strikes; I'm not sure you can keep betting on that.

Of course, that's not all that is different for Jimenez, who was never an elite strikeout pitcher despite his stuff. The biggest positive for Jimenez is his 67.3 percent groundball rate, the highest, by far, of his career. Jimenez was once one of the better groundball pitchers in the game, but has not topped 45 percent since 2011. Is this change for good? 

There does seem to be some good news here, as Jimenez is relying on his sinker on 53.2 percent of his pitches in 2015, compared to 40.2 percent a year ago. He is also getting more groundballs on that pitch, per BrooksBaseball.net, which makes sense. In his career, 10.2 percent of his sinkers have ended up with the batter putting the ball in play, on the ground; that number is just 6.3 percent for his four seam fastball. 

Whether the change in his pitch usage is something Jimenez will sustain moving forward remains to be seen, but it is the one positive sign we can point to about his surprisingly strong start. Still, taken all together, it's hard to find a ton to be encourage about with Jimenez, who looks like much the same pitcher who has frustrated Fantasy players in past years.

Jimenez has been added in 11 percent of CBSSports.com leagues over the last week, and is now up to 79 percent ownership. I wish I could tell you it's going to work out, but this feels like a movie we've seen before with Jimenez, and I'm no longer buying it.