Why I don't fully trust Catch Probability

[Warehouse]

Just now, Warehouse said:

Actually, the catch probability seems to have been updated to 44% based on wall proximity.

Go to Ryan McKenna’s statcast page.  You’ll see four boxes that say Statcast, Standard, Splits, and Game Logs.   Below that is a dropdown box for Batting, Fielding, Running, etc. Select Fielding.  Scroll down to Statcast Fielding Breakdown.  Make sure Fielder’s Perspective is selected. Click on the one dot.  The catch probability, hang time, and distance needed will pop and you will be redirected to a clip of the catch.  This is from the mobile web interface so it might be different from a desktop.

It’s 45% in the dot but shows as 44% in table above (not rounded). Yesterday, it was only available on Toro’s statcast page and showed as 85%.

[bpilktree]

13 hours ago, Fiver6565 said:

I only watched the first three, and then the 85% Mullins catch.  What is the highest % these can go - is it 100?  I'm not sure how that Mullins catch wasn't 100 if so.  It was a lazy pop fly.

The Cowser catches at the top of the list probably required a good jump, but those low % numbers are a bit much.  Especially the 5% one.  How is that a 5% catch while the Mckenna catch is 85?  They aren't that dissimilar other than one being in RF and one in LF. 

Maybe the deep wall somehow plays into the numbers on LF balls?

I think the wall and stadium does make a difference.  The 5% on Cowser first catch was not that hard but it is probably in the stands in almost all other parks so it gets a low percentage.  It would be interesting to go look at a few balls to right in Yankee stadium or left in Boston and see if some of the percentages of balls off walls or homers are on there higher then should be. 

[baltfan]

22 hours ago, Warehouse said:

Actually, the catch probability seems to have been updated to 44% based on wall proximity.

Go to Ryan McKenna’s statcast page.  You’ll see four boxes that say Statcast, Standard, Splits, and Game Logs.   Below that is a dropdown box for Batting, Fielding, Running, etc. Select Fielding.  Scroll down to Statcast Fielding Breakdown.  Make sure Fielder’s Perspective is selected. Click on the one dot.  The catch probability, hang time, and distance needed will pop and you will be redirected to a clip of the catch.  This is from the mobile web interface so it might be different from a desktop.

Crazy, this works for McKenna and doesn't for Gunnar.  For Gunnar, Batter's Perspective is the only choice.

[Yossarian]

So how does this work?  If you look at the same batted ball  do the hit probability for the batter and the catch probability for the fielder always equal 100%?  That is,  if you see a catch probability of 10% for an average fielder,  does that always mean it is a 90% hit probability for the batter?

[Warehouse]

1 hour ago, baltfan said:

Crazy, this works for McKenna and doesn't for Gunnar.  For Gunnar, Batter's Perspective is the only choice.

I think this view is only for outfield balls.

[Warehouse]

1 hour ago, Yossarian said:

So how does this work?  If you look at the same batted ball  do the hit probability for the batter and the catch probability for the fielder always equal 100%?  That is,  if you see a catch probability of 10% for an average fielder,  does that always mean it is a 90% hit probability for the batter?

Whether Batter or Fielder perspective is selected, it only shows catch probability, not hit probability.  

There is also expected batting average (xBA), which is not the inverse of catch probability because it only considers launch angle and exit velocity and doesn’t account for spray angle or distance from fielder.

[Yossarian]

46 minutes ago, Warehouse said:

Whether Batter or Fielder perspective is selected, it only shows catch probability, not hit probability.  

There is also expected batting average (xBA), which is not the inverse of catch probability because it only considers launch angle and exit velocity and doesn’t account for spray angle or distance from fielder.

Thank you. 

[brooks1083]

I would love for someone to explain or justify to me how in the world Mullins catch on 4/15 is listed at 65% catch probability. There are a couple of guys in the league that make that catch but it’s a very short list. Maybe I just don’t understand the stat.

[InsideCoroner]

On 4/30/2024 at 8:10 PM, AlbNYfan said:

There was a diving, foul ball catch in front of the 3rd base dugout by AR a few weeks ago...statcast gave it a high probability of catch number 80% ????

That’s absurd, he slid as he was running out of room approaching the dugout and made a great catch. I wonder if the catch probability takes things like field dimensions into consideration. It’s probably an 80% probability in Oakland, but that’s about it.

[Tony-OH]

On 5/1/2024 at 2:15 AM, bpilktree said:

I think the wall and stadium does make a difference.  The 5% on Cowser first catch was not that hard but it is probably in the stands in almost all other parks so it gets a low percentage.  It would be interesting to go look at a few balls to right in Yankee stadium or left in Boston and see if some of the percentages of balls off walls or homers are on there higher then should be. 

This is a real interesting point and something I never considered. I don't think stadiums and walls are considered in the catch percentages and with Camden Yards being so big in left field now, Cowser will certainly get to balls that most outfielders won't because they would be home runs. Hmm, something to keep an eye on.

[Tony-OH]

15 hours ago, baltfan said:

Crazy, this works for McKenna and doesn't for Gunnar.  For Gunnar, Batter's Perspective is the only choice.

It's only a choice for outfielders. There is no catch percentage for infielders.

[sportsfan8703]

2 minutes ago, Tony-OH said:

It's only a choice for outfielders. There is no catch percentage for infielders.

With the naked eye, do you think Gunnar makes that play on the Trevino single up the middle about 1 in every 5 times?  Better or worse? Catcher running. Gunnar slipped. 

[Frobby]

On 4/30/2024 at 3:20 PM, Tony-OH said:

I do think that statcast needs some tweaking. While it's promising and I love the concept, there is no doubt it's kicking out some wonky catch percentages. If you check out the graphs of the catches, they graph correctly to 1-5 star catches, but the catch percentages can be all over the place on some balls. I also have some concerns over the infield OAA.

 

I wonder if there are some data entry errors in populating those graphs.  A two-star catch is supposed to equate to 76-90% catch probability, but if you look at Cowser’s chart, the catch that’s scored a 20% catch probability shows up as a two-star catch.  Looking at the video, I’d bet it was an 80% catch probability and somehow the probabilities (catch vs. non-catch) got inverted.   It just doesn’t look like that tough a catch.  

[baltfan]

5 hours ago, Tony-OH said:

It's only a choice for outfielders. There is no catch percentage for infielders.

Thanks.  I wish I could see the plays for infielders that are plus and minus for OOA.