A sinker is generally a mis-nomer, as usually we are talking about guys that get good sink on their two-seam fastball, and command it well down in the zone. Some players grip the ball in a couple different ways, but thinking about my sample, I believe most of those guys just throw “heavy” two-seam fastballs.

The reason you hear about the tired thing is because, with some of the guys, throwing harder flattens the pitch out. If they have nice, easy arm action, their grip and their motion does the sinking for them. If they rear back and throw hard, it flattens out a bit. I’m not sure how true this is (I feel like someone did a pitch F/X study of this, but I can’t find it), but it’s certainly an ardent belief of coaches … and thus, commentators.

Also, perhaps you can answer a few of my questions about sinkers. What is the difference between a sinker and a fastball that is down in the zone consistently? And why is it that I have heard commentators say that a sinker has more “sink” when the pitcher’s arm gets tired?

Thanks for the great info.

I also think a reason you’re seeing those numbers is backspin. This is a skill that a lot of these players have barely heard of before professional baseball, but one that is preached to them constantly by hitting coaches. Backspin, as my tennis playing comrades can tell you, will make the ball go further than hitting the ball with topspin, and makes home runs more likely. It also, though, will keep the ball in the air longer, so if the ball doesn’t go over the fence, it’s probably easier to catch. I think these players learning and applying backspin as they progress up the minors might be reflected in your numbers.

As for bunts, oops on me. If the same % of ground balls make it to the outfield for hits, but a much lower percentage of grounders are turned into outs (from division I’s 61% to minors 64-66% to majors 69%), then yeah, we’re looking at errors and infield hits of all varieties. The hard charge from third and the throw from deep in the hole at short are difficult, and you definitely see a much lower % of Zimmermans and Furcals in the minors.

My hypothesis is that if you have two roughly equal batters in A ball, the one with more HRs (higher vertical angle) gets promoted. Therefor the outfielder in MLB and the high minors is not chasing the same type of FBs that the outfielders in the low minors are.

I plan on testing this by looking at the FBH% of batters who have been promoted to see if their rates as batters change or are stable as they are promoted, and if the guys with the higher FBH% tend to not get promoted.

On the GBs, I wasn’t talking about bunt hits. Infield grounders where the batter is safe at 1b can be scored as either an error or an IFH, depending on the judgement of the scorer. Therefor, I like to lump them together as a measure of the infielder’s ‘hands’. What I do know for sure is what pct of infield grounders the defender converted into an out.

The infield data makes sense without much too much thought. Younger players tend to have better range (but less awareness and positioning) and “clankier” gloves, especially in the lower minors. Hitting grounders for base hits is not a skill, and thus remains constant. Bunting for hits certainly is a skill, although one wonders why hitters would be ahead of fielders early on.

As for fly ball rates, that’s a tougher one. Certainly, tracking the more difficult flies gets polished as a player ages (up until physical limitations set in), but that’s probably not it.

My guess involves higher K rates in the low minors — the lack of plate discipline and adjustment to wooden bats tends to favor the pitchers early on, so fewer batted balls are getting to the outfield. The flies-closer-to-LDs you mention is probably true, so the balls that DO make it out there tend to be hit more solidly, i.e. less can-o-corns and more ropes to the gap.

I’m not sold on that last explanation, though. Could it really be as simple as that? Good high heat and movement that turns into fly outs at the major league level is more likely to be a K in the minors?

Keep it coming.

As for Porcello, he’s going to need to get significantly better next year just to stay the same, as the difference between Polanco and his replacement (be it Scott Sizemore, Ramon Santiago, or someone else) is likely to hurt him, badly. The guy was a rock.

The second thing was that even though ground ball hit rates were very stable, fly ball hit rates in MLB are only about half of what they are in Rookie ball (17% to 35%). If infielder’s range doesn’t change, why does it for the outfielders? High fly ball hit rates suggest lower vertical angles (more towards LDs and away from popups), but there’s probably a bias towards advancing HR hitters, who hit the ball higher in the air and are easier to catch. So here, the difference is likely in the batters and not the outfielders.

Yes, you can make up for this just by striking everybody out. And from now until the end of time, the great K/9 pitchers will (and should!) dominate prospect rankings. This is just a call to not forget that there’s another route to success.