A New Way of Looking at Expected Stats + Leaderboard

Crosby Spencer provides his first article for the Dugout explaining his way of building out expected stats and provides an in-depth leaderboard.

On February 27^th, 2010 Steve Slowinski wrote an article on Fangraphs titled “Park Factors”. Here’s an excerpt from that article:

“The Noble Goal

If you had the power to do so, you’d want to know how every single plate appearance would play out in all 30 MLB parks. If it turned into a single in the park of interest and then went for a single in 25 other parks, an out in three, and a double in one, you’d have a good sense of the way the parks played. The park that allowed the double would be a hitter’s park and the ones that created outs would be more pitcher-friendly. But unfortunately, we don’t have that kind of data.

We want to know how parks influence each moment of the game, but we simply don’t have granular enough data to really get there. A ball hit at 15 degrees directly over the shortstop while traveling at 93 miles per hour will travel how far and land where? That’s basically what we want to know for every possible angle and velocity, but we just don’t have the data and we don’t have it for every type of weather in every park.

Instead, we have to settle for approximations.”

Now, we do have that data!

Using the data provided by Baseballsavant.com I’m going to analyze the results of all Batted Ball Events (BBE) from 2022 – 2023 (The Humidor Era) by Exit Velocity (EV), Launch Angle (LA), handedness (RHB and LHB), hit location (LF, LCF, CF, RCF, RF) and whether the ball was Pulled, hit to the Opposite field, Pulled to an Alley, hit to the Opposite Alley or Centered. Taking all of these factors into account, we come up with the average for how EVERY batted ball event played out in all 30 MLB stadiums during the 2022 – 2023 seasons. Below is an example of some of these averages:

All BBEs in 2022-2023 with an exit velocity of 98 mph and a launch angle of 26 degrees.

All BBEs in 2022-2023 with an exit velocity of 98 mph and a launch angle of 26 degrees that were pulled.

All BBEs in 2022-2023 with an exit velocity of 98 mph and a launch angle of 26 degrees that were pulled to an Alley.

All BBEs in 2022-2023 with an exit velocity of 98 mph and a launch angle of 26 degrees that were centered.

All BBEs in 2022-2023 with an exit velocity of 98 mph and a launch angle of 26 degrees hit to an opposite field Alley.

All BBEs in 2022-2023 with an exit velocity of 98 mph and a launch angle of 26 degrees that were hit the opposite way.

When we analyze these sets of data we can further see why it’s so important to use more than just Exit Velocity and Launch Angle. If we only use those two factors, we would be assigning an expected AVG of .392 and an expected HR rate of 16% for every ball hit at an Exit Velocity of 98 MPH and a Launch Angle of 26 degrees. However, if that ball that’s hit at 98/26 goes to Center Field it’s an out 89.3% of the time with a 0.00% chance of leaving the yard. Conversely, when Pulled, that same 98/26 batted ball has an 85.2% of being a hit with a 63% chance of being a Home Run.

Once we assemble all of the outcomes for the seasons being analyzed, we can then generate the Expected Stats for each and every Batted Ball Event and its subsets of Handedness and Hit Locations. This data now gives us the Average MLB Park in order to compare the Park’s Actual Outcomes to the MLB Average Expected Outcomes. Further, when we factor in the impacts of Sprint Speed and the composite Schedule Factors for each MLB team, we can then generate the Expected Stats for every individual Hitter and Pitcher. A noble goal indeed Mr. Slowinski! Are we having fun yet?!

How We Differ from Savant

All BBEs in 2022-2023 with an exit velocity of 98 mph and a launch angle of 26 degrees.

Savant’s Expected Stats in 2023 at an exit velocity of 98 mph and a launch angle of 26 degrees.

Candidly, there’s no way for me to know what data sets Savant uses to generate their Expected Stats. However, given that their XWOBA is .102 points greater than ours, I’m assuming that they are likely using all Batted Ball Events from 2015 through 2023, as the Batted Ball Events of 2015 through 2021 generated a greater WOBA at the analyzed EV/LA of 98/26 than those Batted Ball Events during the Humidor Era of 2022 through 2023. I know Savant assigns the same xwOBA no matter the Batter’s Handedness or the hit Location. From the data we laid out earlier, I feel our Expected Outcomes are more accurate. Obviously, I’m biased, so I’ll let you, the reader, decide. 

Editors Note:

Crosby Spencer is one of the sharpest data minds out there. These expected stats are an incredible resource for you to use to help you win your leagues. This data will be put into our Tableau database soon. But here is a massive excel sheet with expected numbers on all hitters between 2022 and 2023 weighed against actual performance. Data is for subscribers only so click the sub button to get an edge.