Towards an Objective Quantification of Player Offensive Speed: Just How Fast Are/Aren't Recent Astros?

Tweaking my Fielding and Ballpark-Independent Outcomes (FaBIO) evaluation system for application to offensive players has created a need to quantify parameters that were not necessary in pitcher analyses, namely the speed and power of individual batters. Below you will see how early attempts at quantifying position player speed on the offensive side of the ball are progressing, and what those results say about current and recent Astros.


Methods: Quantifying Offensive Speed

The present need to for this arises as the runs value associated with a groundball increases (gets more positive) as the batter's speed increases. Without the benefit of a handy max-effort 40 yard dash (or better yet a 90 feet one) spring training time on every position player, one has to generate methods from in-game speed-sensitive data to stratify players based on that parameter.

Rating One: Stolen Bases per Opportunity

This formula is stolen bases minus non-picked off caught stealings, divided by the number of stolen base opportunities (times the player was stationed on first or second with the next base unoccupied). The players of a league who meet the minimum plate appearances threshold for the study group are ultimately percentile ranked from highest percentage to lowest on a 100 to 0 scale. Besides simply speed the result involves both the quality of the jump the player gets as well as player/manager/coach aggression.

Rating Two: Extra Bases Taken on Other Batter's Singles and Doubles per Opportunity

This is the number of times the player successfully went first to third or second to home on a single or first to home on a double, divided by the number of opportunities to do so. Leads and coach/player aggression also factor in here, as do field factors such as outfield fence proximities. These advance opportunities present much more seldom than the former type do. The league qualifiers are ultimately percentile ranked from highest percentage to lowest on a 100 to 0 scale, with 97 being plus plus, 84 being plus, 50 league average, 16 minus, and 3 minus minus.

Rating Three: Infield Singles per Infield Groundball

This amounts to singles per nonbunt infield groundballs (groundballs fielded by an infielder), and players are again ranked on the 100 to 0 scale. Infield groundballs occur less often than the stolen base opportunities do but quite a bit more than extra base advance opportunities do. The jump out of the batter's box gets to be important here beyond speed.

Overall Player Offensive Speed

An Overall Offensive Speed Rating can be generated by weight-averaging the 3 prior ratings based on the player's relative frequency of each opportunity type. This, too, will be expressed on the 100 to 0 scale.



2015 Houston Astros

The following numbers express how 2015 Astros fared relative to the standards of their league(s).


  • Jake Marisnick already rates within the majors' top handful of offensive speed weapons, placing near the top in all 3 individual categories.
  • Jose Altuve profiles as a near plus plus offensive speed performer.
  • George Springer and Carlos Correa rated just a few percentile points under plus territory.
  • Carlos Gomez' Overall Offensive Speed Rating declined in 2015 owing to a plunge in his ability to beat the rap at first on infield grounders (2015: 5.4% success; 2014: 16.2% success, which amounted to a 99th percentile rating).
  • Colby Rasmus is a somewhat surprising non-infield-singler as his miniscule 2015 rate of the event was in stride with the 2014 number.


Combined 2015 and 2014 Seasons: Recent Houston Astros and Other MLBers of Interest

Going back another MLB season to 2014 and combining the results of the two seasons yields the following results, with select non-Astros included as data frames of reference.


  • Marisnick's statistical similarity to Drew Stubbs may prove to be an omen if he continues to struggle with walking and making contact.
  • Altuve could stand to be more aggressive in taking the extra base on others' hits.
  • 6'5" Domingo Santana is showing surprising offensive speed in the very early going.
  • Offseason minor league free agent signee Eury Perez has flashed near plus offensive speed over his small sample of mostly 2015 MLB work.


  • Rasmus' aversion to the infield single would explain part of his bias towards a lower batting average.
  • Among non-catchers, Marwin Gonzalez may be the logical heir to Matt Dominguez' vacated turtle shell.
  • Kiké Hernandez looks the part of an anti-Santana as a smaller player who profiles to be very slow offensively in the seminal stages of his MLB career.