"This means that a pitch that might hit Jeff Francoeur's knee, and he's as likely to swing at it as a pitch right down the pipe to Gardner."

Not to nitpick or anything, but that's not true. While you can say with a level of confidence that Gardner will swing at a pitch down the middle 50% of the time, that's not the same as Francoeur swinging at a pitch coming toward his knee. The 50% swing probability distribution is much more spread out for Francoeur, and the contour lines only show where the batter swings 50% of the time on average, not in every single area within the contours.

Otherwise, this is a cool idea / visual representation of swing-heavy hitters. I think filled contour plots would be able to visually describe what I mentioned above ;)

Albert, I'm not sure I follow your point, but I readily admit I was engaging in some hyperbole with regards to Francoeur. Thanks for commenting.

Do the contour lines represent 50% of Francoeur's swings? Or do they represent the area wherein Francoeur swings (at least) 50% of the time? If the latter, then my earlier comment should be retracted.

Neat stuff Jeremy. Would love to see someone like Pujols or Youkilis' chart sometime. Just to see how often they swing at stuff out of the zone.

Albert, the two things you describe are the same. It is impossible for an area inside a contour line to be predicted at less than 50% or else the contour line would not encircle that part of the graph.

Mr. Jorgan, their zones are probably what you would expect.

Is your first sentence sarcastic? Yes, right? In those 119 games he's hitting .230/.286/.366. As a Met fan just have to put that out there.

The funny thing was, coming into this season, the "conventional wisdom" was that Gardner was going to have to get a little more aggressive to succeed in the majors. Show pitchers they can't just throw him three fastballs down the middle.

And yet...

I would totally sue my plastic surgeon if my name were Francoeur Gardner.

Really great visuals, Jeremy. How are you making them? I dabble with PFX and I love stuff like this.

It's easy to slam Francouer swing at a pitch headed for his knee, but shouldn't Gardner be swinging at those fat fat pitches 80% of the time (or whatever) instead of only 50%?

Expanding on the prior post a bit, one of the stats I've never seen is how often various batter don't swing at fat pitches. We have ZSw% at Fangraphs, but that includes all strikes--hitters strikes and pitchers strikes. These are 2 different animals in terms of how often a batter should swing.

Can you generate a fat pitch circle--a bit larger than the circle for Gardner, I would think--and show how often batters swing at these pitches?

Cyclones, no sarcasm. I love Francoeur.

Rob, that might have been the conventional belief, but the conventional wisdom was that Gardner was awesome.

Chris, I use R.

DCS, funny, I was just talking about Gardner's approach with some smart baseball people, and the answer is probably no, he should not swing more often. Instead, more people should be willing to take called third strikes.

What you suggest about generating a fat pitch circle would be much more complicated than what you outline. I'll think about it.

Yes, batters should take more called third strikes, but only on pitches at the margin that are as likely to be called a ball or a strike. Certainly not on fat fastballs down the pipe. Batters shouldn't let these go by very often, even on the first pitch.