MLB's new statcast data gives us ways to evaluate fantasy baseball hitters in ways we previously couldn't

Instead of looking at just outcomes, I think it's important to also consider the quality of contact a hitter makes off the bat. It's not everything, of course. For one, it doesn't take into account defensive positioning; if a batter can't use the whole field, teams are going to position their defenders in areas where most of his batted balls go. It doesn't take into account hit placement, either, which some hitters with shorter strokes excel at. Anyone who watched Ichiro hit knows how much of a master he was at placing the ball in areas that defenders were not.

But there is an element of randomness to the game of baseball, one that just looking at outcomes doesn't catch. Sometimes, batters hit rockets that would be extra base hits if it traveled a few feet to the left or right of a fielder. The conditions during the game can have varying impacts on how the baseball travels once it leaves the bat. The ball interacts with the air after it leaves the bat, and different environments can give the ball different levels of air resistance based on things like temperature during the game, wind patterns, humidity, and ballpark elevation.

I watched Yoenis Cespedes hit a shot at Citi Field during the second week of April that probably would have landed near the second deck on a nicer day, but the howling inward wind and colder temperature gave the ball too much resistance as it traveled through the outfield and kept it in the park. Cespedes struck the ball incredibly well off the bat, but due to factors outside of his control, the outcome changed from a home run to an out.

Even the individual baseball used can have an effect on how far a batted ball travels. In an experiment done by Baseball Prospectus, researchers found that different MLB baseball lots traveled different distances under the same launching conditions, primarily because each individual lot had a different impact on drag. There was even individual variation within the same ball lots, with distances varying sometimes up to 30 feet based on the individual construction of each ball. That could be the difference between an extra base hit or a fly out through no fault of the hitter himself. Different levels of mud, rosin, and pine tar that get on a ball may affect the distance the ball travels after leaving the bat, too.

What sticks out most to me about this is I remember listening to an interview a few years ago with an outstanding former writer for a notable baseball website, who is currently working in the scouting department of an MLB team. He talked about how professional talent evaluators inside baseball heavily take into account the type of contact a hitter generates off the bat when making their player evaluations. Hitters will often get down on themselves after lining out on a screaming line drive right at the third baseman, but they shouldn't because that good type of contact is exactly what many of these progressive front offices are evaluating them on. If this is how the highly paid front offices with Ivy League degrees are evaluating players, it makes sense that fantasy owners should consider doing something similar to this, too.

Exit velocity + vertical launch angle + horizontal spray angle

With the debut of statcast last year, more objective ways of measuring the type of contact hitters make are now available, like using the combination of exit velocity off the bat and trajectory based on launch and spray angles. Launch angles just went public a few weeks ago.

Statcast classifies batted balls with vertical launch angles between 10 and 25 degrees as line drives. Below 10 degrees is a ground ball. Fly balls are above 25 degrees, with over 50 degrees considered pop ups.

Where launch angles are helpful is differentiating between different types of ground balls and fly balls. A ground ball hit with a 5 degree launch angle is a lot different than a ground ball hit at a -10 degree launch angle. According to statcast, the league hit .438 on ground balls between 5 and 0 degrees but just .168 on ground balls hit between -10 and -15 degrees last season. The reason is because the more negative the launch angle, the quicker and more downward the ball slams into the ground after leaving the bat, slowing down the momentum of the ball through the infield and making it more difficult to go through past a fielder.

Launch angles also help reduce some of the subjectivity in classifying line drives. A line drive can mean something different to different people watching a game (is it a low fly ball or a high line drive?)

In addition to vertical launch angles, horizontal spray angles are also included. -45 degrees is down the left field line. 0 degrees is straightaway center field. 45 degrees is down the right field line.

Creating a more objective "well hit rate" statistic for fantasy baseball based on statcast data

According to the statcast data, these categories are the best types of contact:

• Exit velocities of 95+ mph hit between a 0 and 9 degree launch angle (hard ground balls)
• Launch angles between 10 degree and 19 degrees (line drives at any speed)
• Exit velocities of 100+ mph hit between a 20 degree and 40 degree launch angle (hard fly balls)
• Exit velocities of 95-99 mph hit between a 20 degree and 40 degree launch angle with a horizontal spray angle within 20 degrees of the lines (well struck fly balls to LF or RF)

Category 1: hard ground balls: According to statcast, batted balls that left the bat with exit velocities of 95+ mph and a launch angle between 0 and 9 degrees had a batting average of .620 last year with an OPS of 1.300. A lot of singles fall into this category. The breakdown for batted balls hit in this range is 54% singles, 7% doubles, 1% triples and 0% home runs.

Category 2: line drives at any speed: Batted balls that were vertically launched at any speed between 10 and 19 degrees had a batting average of .700 with a 1.650 OPS. Even softly hit balls go for hits here; the league hit .660 on batted balls that left the bat at less than 85 mph between 10 and 19 degree launch angles. Slap hitters who hit for high BABIPs but low slugging percentages probably record a lot of batted balls in this range.

Category 3: hard fly balls: Batted balls that left the bat at 100+ mph with a launch angle between 20 and 40 degrees had a batting average of .800 with a 3.600 OPS. Tons of extra base hits come here. The breakdown here is 1% singles, 15% doubles, 2.5% triples, and 61% home runs. This appears to be the highest value contact range.

Category 4: well hit fly balls to LF or RF: Horizontal angle can be important, too. The league hit .570 with a 2.500 OPS on batted balls hit 95-99 mph with a launch angle of 20-40 degrees and a spray angle within 20 degrees of the left field line last year. It came with a 38% home run rate. The league hit .400 with a 1.600 OPS and a 22% home run rate under these conditions to right field. The horizontal angle is important for fly balls under 100 mph because a ball that leaves the bat at 97 mph with a 35 degree launch angle to CF is usually a fly out, but if it's hit to LF or RF, it has a decent chance to go for a home run.

Taking a little bit from all of the categories above to make one "well hit rate" stat: batters hit .750 with a 2.500 OPS on batted balls hit 100+ mph between a 5 degree and 40 degree vertical launch angle last season. Here are the 5 players who generated the most 100+ mph batted balls with a launch angle between 5 and 40 degrees from 2015:

Player	BIP
1. Josh Donaldson	109
2. Mike Trout	109
3. Yoenis Cespedes	106
4. Paul Goldschmidt	106
5. Nelson Cruz	105

With Donaldson, Trout, Cespedes, Goldschmidt and Cruz as the top 5, it passes the eye test.

A well hit stat is not gospel

Like it was stated at the top, hitting the ball "well" on paper isn't everything. It needs to be combined with other measures to paint a complete picture. A well hit stat does not take into account hit placement, or infield shifts, which can eat up well hit balls. If a player can't use the whole field, teams are going to position their defenders in areas where most of his batted balls go, turning more well hit balls into outs.

A well hit stat using just exit velo + angle doesn't take into account batted ball spin, either, which is not a public metric. Ferocious topspin can make hard line drives dive into the ground and away from defenders more aggressively than a line drive without as much topspin. Sidespin can make a ball slice or hook away from defenders. Backspin gives a ball more lift, and might make line drives carry further (backspin on fly balls apparently only has a small impact on distance).

I think this method could be a good way to get some additional information on hitters and how well they're hitting the ball, because there is an element of randomness to the game of baseball that can sometimes distort outcomes. The Cespedes example I cited earlier is a good representation of that.

2016 leaders in well hit rate using statcast data

Here are the top 50 in "well hit rate" through April 27 as defined by batted balls that leave the bat at 100+ mph between a 5 degree and 40 degree vertical launch angle. MLB average % of at bats ending with a batted ball 100+ mph between a 5-40 degree LA is 9.8%.

Player	# of BIP	% of ABs
Manny Machado	18	22.8%
Domingo Santana	18	24.6%
David Ortiz	17	27.4%
George Springer	16	18.6%
Mookie Betts	15	16.1%
Bryce Harper	15	23.4%
Yasmany Tomas	15	19.7%
Chris Carter	14	21.9%
Jose Altuve	14	16.9%
Mark Trumbo	14	18.6%
Dexter Fowler	14	20.6%
Ryan Braun	14	20.9%
Matt Kemp	14	17.5%
Trevor Story	13	16.9%
Wil Myers	13	15.3%
Josh Donaldson	13	14.8%
Gregory Polanco	13	17.3%
Colby Rasmus	12	18.2%
Miguel Cabrera	12	16.9%
Anthony Rendon	12	15.2%
Yoenis Cespedes	12	20.0%
Nick Castellanos	12	18.5%
J.D. Martinez	12	16.6%
David Peralta	12	13.8%
Tyler White	12	17.4%
Robinson Cano	12	15.0%
Edwin Encarnacion	12	14.1%
Andrew McCutchen	12	15.0%
Jean Segura	12	12.6%
Mike Moustakas	12	16.0%
Michael Conforto	11	18.0%
J.J. Hardy	11	18.3%
Maikel Franco	11	14.5%
Brandon Belt	11	15.3%
Ryan Howard	11	17.7%
David Wright	11	16.4%
Todd Frazier	11	13.6%
Eric Hosmer	11	14.3%
Byung Ho Park	11	20.0%
Nelson Cruz	11	14.3%
Miguel Sano	11	14.9%
Mike Trout	11	14.9%
Neil Walker	11	14.3%
Starlin Castro	11	15.3%
Steve Souza Jr	11	18.0%
Victor Martinez	11	18.0%
Kris Bryant	11	13.4%
Logan Forsythe	11	15.3%

And here are the top performers broke down into subgroups from the categories above that might get overlooked in the "well hit rate" stat:

Top 10 in exit velocities of 95+ mph hit between a 0 and 9 degree launch angle (hard ground balls)

Anthony Rendon, 12

Domingo Santana, 11

Adonis Garcia, 10

Jean Segura, 9

Eric Hosmer, 9

Christian Yelich, 9

Kyle Seager, 9

Chase Utley, 9

Daniel Murphy, 9

Khris Davis, 9

Top 10 in launch angles between 10 degree and 19 degrees (line drives at any speed):

Josh Harrison, 18

Jose Altuve, 15

Starling Marte, 15

Alexei Ramirez, 15

Miguel Sano, 14

Angel Pagan, 14

Maikel Franco, 13

Chase Utley, 12

Dustin Pedroia, 12

Mookie Betts, 12

Eduardo Escobar, 12

Adrian Gonzalez, 12

Francisco Cervelli, 12

Top 10 in exit velocities of 100+ mph hit between a 20 degree and 40 degree launch angle (hard fly balls)

Matt Kemp, 10

David Ortiz, 10

Andrew McCutchen, 10

Trevor Story, 9

Bryce Harper, 8

Ryan Howard, 8

Tyler White, 8

Mookie Betts, 8

Chris Davis, 8

Anthony Rizzo, 7

Yasmany Tomas, 7

Kendrys Morales, 7

Troy Tulowitzki, 7

Josh Donaldson, 7

Nolan Arenado, 7

Wil Myers, 7

Neil Walker, 7

Top 10 in exit velocities of 95-99 mph hit between a 20 degree and 40 degree launch angle with a horizontal spray angle within 20 degrees of the lines (well struck fly balls to LF or RF)

Neil Walker, 3

Stephen Piscotty, 3

Jose Altuve, 3

Josh Donaldson, 2

Victor Martinez, 2

Mark Teixeira, 2

Wellington Castillo, 2

Jose Ramirez, 2

Nelson Cruz, 2

Edwin Encarnacion, 2

Anthony Rendon, 2

Dustin Pedroia, 2

Scooter Gennett, 2

Chris Stewart, 2

Joe Mauer, 2

Matt Adams, 2

Mike Moustakas, 2