Comparing Trevor Williams and 2014 Edinson Volquez

Trevor Williams will take the hill this afternoon as the Pittsburgh Pirates will look to get a game over .500, sweep consecutive series, and win six straight games.  The way Williams is pitching on the season is reminiscent to 2014.

Trevor Williams will enter the game with a 3.15 ERA, the best on the Pirates staff by 0.25 runs, with Jameson Taillon possessing a 3.40 ERA.  If the season ended today, Williams would have the fourth lowest ERA among qualified Pirates starters since 2000.

Part of that comes from being historically good in the second half this season.  Since the All-Star game started in 1933, here are the top five pitchers in ERA in the second half the season (minimum 10 starts):

Williams has only made eight starts, but after today against the Marlins, he’ll be looking at games at Milwaukee, home against Milwaukee, and a game at Chicago.  He’ll have four more starts, qualifying for the leaderboard above, and if he continues to suppress runs at this rate, he’ll have the record.

But back to the Pirates list.  Since 2000, here are the top five qualified pitchers in ERA:

Williams slots right behind a pitcher and a year that is reminiscent of his current season, drastically outperforming his metrics.  Here are the notable metrics for Volquez in 2014 and Williams so far this season:

Both Williams and Volquez generated weak contact, the league average in 2018 in hard contact percentage is 35.8 percent.  Similarly, both struck out batters and got swinging strikes at a below average rate, though Volquez was much closer to the average than Williams and the game has evolved in just five seasons.

The two pitchers outperformed (outperforming in Williams case) their FIP by a run and both essentially had the same FIP.  After 2014, Volquez signed a two-year deal worth $20 million with the Kansas City Royals.  Williams will be pre arbitration eligible in 2019.

In his two seasons with Kansas City, Volquez posted a 4.43 ERA and 4.19 FIP, split into 3.55 ERA/3.82 FIP and 5.37 ERA/4.57 FIP in 2015 and 2016.  He only posted a 17.2 percent strikeout rate and 9.0 percent swinging strike rate.  The game evolved and the value of the strikeout and swinging strike has increased, part of the reason why getting Chris Archer is beneficial.

The same concern can be happening with Williams, who had a 4.07 ERA last season and was a projected 4.66 ERA by STEAMER at the start of the season.  Deserved Run Average (DRA) is an estimator for RA9.  Williams has a DRA of 4.47 (SD of 0.79) with a 3.45 RA9.

When Williams regresses, it won’t make him a bad pitcher.  A RA9 around 4.50 is average (his DRA- is 100, or average) and that’s a starter you want in your rotation.  The Pirates will be led by Jameson Taillon, Chris Archer, and Joe Musgrove, a making of a strong top three, and Williams and another starter rounding out the four and five spots in some order.  Taillon, Archer, and Musgrove all have DRA- lower than 100, with Archer being the closest to average at 98.

But for now, Williams is pitching lights out like Volquez did in 2014.  The biggest difference is Williams is pitching for a personal record while Volquez was trying to keep the Pirates in the divisional race and ended up starting the wild card game.  Hopefully Williams can keep pitching lights out for the rest of the season and secure the record before the regression comes for him.

*Numbers from Fangraphs and Baseball-Reference