The Buffalo Bisons will Change your Swing

Much has been made of Lourdes Gurriel Jr. and his revelation since returning from Triple-A Buffalo. Tony Wolfe of Fangraphs noted Gurriel Jr.’s newfound ability to crush sliders, and Tim Jackson of Pitcher List, broke down the slight change in Gurriel Jr.’s swing and how he’s drastically improved his exit velocity.

On top of the mechanical change Gurriel Jr. has also altered his batted ball profile.

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LD% GB% FB% Pull Centre Oppo Launch Angle
Mar 28-April 14 14.3% 42.9% 42.9% 32.1% 28.6% 39.3% 15.3
May 24-Present 20.0% 36.5% 43.5% 41.7% 37.4% 20.9% 13.8

He has slightly lowered his launch angle but the big change is in where he is hitting the ball. He is pulling the ball significantly more and putting it on the ground less. These are both good things, especially in a hitter’s park like Rogers Centre. Seeing this it’s no surprise that he has hit 16 home runs since his recall, with 10 being hit out to left field.

Gurriel Jr.’s change and success lead me to look at other players who have spent time in Buffalo this season. It hasn’t been to the same degree but Teoscar Hernández made a change to his batting stance while in Buffalo.

While he hasn’t had the same success as Gurriel Jr., Hernández has been better though still has been a below average hitter since returning (87 wRC+) which is a big improvement on what he was before he was sent down (48 wRC+). Looking at his batted ball profile he has made some slight alterations there as well.

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LD% GB% FB% Pull Centre Oppo Launch Angle
Mar 28-May 15 17.6% 40.0% 42.4% 47.7% 31.4% 20.9% 15.6
June 5-present 15.0% 43.3% 41.7% 43.3% 25.0% 31.7% 14.8

These aren’t as drastic as Gurriel Jr.’s but a change is there, more balls to the opposite the field. Typically when players change their swing/approach they are trying to add power and hit home runs. With Hernández he didn’t need to alter his approach at the plate to hit for more power. He already hits the ball incredibly hard and has great raw power, and with the juiced ball it makes sense for him to tap into some of that opposite field power.

Hernández’s biggest problem was with strikeouts and overall lack of contact. By lowering his hands he is shortening the bat path to the ball which has helped him make more contact.

K% BB% O-Contact% Z-Contact% Contact% SwingStr%
Mar 28-May 15 29.8% 9.2% 50.4% 78.5% 66.7% 15.7%
June 5-Present 30.5% 6.3% 58.8% 79.1% 70.8% 14.1%

It hasn’t reflected in his strikeout rate but he is making more contact, particularly on pitches outside of the zone. He’s also reduced his swinging strike rate. Ideally you would have liked to have seen him maintain his walk rate but this is the trade off with his aggressive approach.

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Buffalo hasn’t just helped out young players. Eric Sogard started the season in Buffalo and while it was only a short stay, just 38 at bats, he too has changed his approach at the plate, leading to a career year at age 33.

Here is a Sogard swing from last season.

And one from this season

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The changes are subtle but they are there.  He stands slightly more crouched and has reduced his leg kick.


Sogard, like Gurriel Jr. and Hernández has seen a drastic change in his batted ball mix.

LD% GB% FB% Pull Centre Oppo Launch Angle
2018 27.0% 36.5% 36.5% 36.8% 38.2% 25.0% 15.8
2019 23.4% 31.8% 44.8% 36.9% 32.3% 30.8% 19.2

Sogard has raised his launch angle which coincides with his increase in fly balls. He has always been a player that makes a lot of contact and that hasn’t changed. What he has done is put more balls into the air and with the combination of the juiced ball and Rogers Centre has led to a career high nine home runs. Prior to this season Sogard had a career total of 11 home runs.

He only returned to the majors for a short time but Billy McKinney was one other player who made a swing change while down in Buffalo.

It is a very tiny change but McKinney is keeping his hands closer to his chest. He was only back up with the Blue Jays for 11 plate appearances so there is nothing we can take away from his batted ball profile or plate discipline stats. When he is recalled again it will be something to monitor to see if he has made similar changes to the others.

We can’t say for certain whether these changes are coming from the big club when a player is being sent down, or whether it’s from Buffalo when the players arrive there. Regardless the staff with the Bisons deserve praise for working with these players and executing these changes.

Now not every player who is down in Buffalo automatically turns to gold, see Jonathan Davis and Richard Urena, but there is no denying they are doing something right down there. They have worked with four players to alter their swings and approaches at the plate and they have three successes with one still to be determined. For some struggling players on the Major League team like a Brandon Drury or a Rowdy Tellez, maybe a short trip to Buffalo wouldn’t be the worst thing in the world.

  • Cincinnatus C.

    Interesting … but the Buffalo angle isn’t convincing without a control group of guys who’ve been on the major league team all year. Like the TV guys are always harping on about, big league hitters constantly have to be making adjustments over the course of a season. I have a feeling you’ll find some significant differences in Danny Jansen’s or Rowdy Tellez’s swings and batted ball profiles between early April and early July. Looking at Jansen, his GB% has gone down every month and–Buck and Tabby will not like this–his OPPO% is way down since he’s gotten hot. Chances are you’ll find changes in approach corresponding to these changes in results.

    Funny how the leg kick goes in and out of style, and when it’s in it’s obviously the solution and when it’s out it’s obviously the problem.

    • Paul Berthelot

      Absolutely players makes changes throughout the season but we have seen are three players make real significant changes to their approach, which is not something your normally see. Jansen is one and his hot stretch has coincided with him removing the C-flap from his helmet. It looks like he is seeing the ball better getting out in front of it more, pulling it and getting the ball in the air. Looking at Tellez and Drury nothing really stands out in their swings or approach. Even vets like Grichuk and Galvis have stayed the same despite their poor results.