Suppose you wanted to evaluate the performance of a starting pitcher in a particular game. Typically, we would ask questions such as: how many runs, hits, and walks did he allow, and how many batters did he strike out? It would be nice though if we could distill the different pitcher outputs in a game into an easily understandable single number. Fortunately, such a single-number statistic already exists, known as the Bill James Pitcher Game Score (“BJ Score” for short). The BJ Score has a number of nice features:
- It is set up so that an average starting-pitcher performance is scored as 50, giving an easy frame of reference.
- It incorporates many measures of pitching success, including innings pitched (with a bonus for pitching beyond the fourth inning), strikeouts, hits allowed, walks allowed, and runs allowed (more penalty for allowing earned runs than unearned runs). The precise formula is available here. In a nutshell, each pitcher starts out at 50, with points added for good things (e.g., strikeouts) and subtracted for bad things (e.g., hits allowed).
- It allows different kinds of comparisons. Readers can focus on any one pitcher, seeing how he performed against Top 25 opponents vs. unranked opponents; early vs. late in the season; etc. Or one can compare the BJ Scores of a team’s three weekend starters.
Accordingly, I have computed BJ Scores for each Texas Tech game of the 2022 season up until this past Tuesday night. With a lengthy break in the season due to final exams, now would seem a good time to take stock of how Red Raider starting pitchers have fared. The following chart contains this information.
To make things even easier to follow, I have added a color code. Starts shaded in green are good (BJ Score of 56 or higher), the darker the green the better. Scores near the average of 50 (46-55) have a white background. Finally, starts in red shade are bad (45 and lower), the darker the red the worse.
Even without advanced statistics, it is clear at this point in the season that Tech’s best two starters are Andrew Morris, the Friday night guy, and Brandon Birdsell, the Saturday starter. I would still argue that BJ Scores are useful in this context, as they quantify how good these pitchers have been in all of their starts and illustrate the opponents against which they have pitched particularly well or less well. The best BJ Score recorded this season by a Raider pitcher is Birdsell’s 87 at Rice on March 12, in which he pitched six innings allowing no runs, hits, or walks – two Tech errors being the only barrier to perfection – and striking out 15. Another interesting finding (to me at least) is that beginning with his third start of the season (vs. Merrimack), Morris has exceeded a BJ Score of 50 in seven of his last eight starts.
As can also be seen in the chart, for roughly the first half of the season, frequent starters Mason Molina and Chase Hampton were solid, if not spectacular, regularly registering BJ Scores in the 50s and 60s. Beginning with the series at Kansas (KU), however, no starts by anyone other than Morris and Birdsell have been “green” (see the rectangular area in the lower-right corner outlined in black).
Going back to Birdsell’s outing at Rice, many observers lamented that he did not even receive a win on his record, as Rice tied the game 2-2 after Birdsell’s exit and Tech did not score the go-ahead (and ultimately winning) run in a 3-2 victory until long after he had departed. (In addition, Raider relievers allowed Rice three hits, thus falling short of a “no-hitter by committee.”) To that I say, a BJ Score of 87 is far more impressive than an ordinary win. BJ Scores are not influenced by how many runs a pitcher’s teammates score on offense, the way wins are.
Increasingly, baseball observers have been seeing the irrelevance of the win-loss statistic for pitchers, a trend culminating in New York Mets pitcher Jacob DeGrom capturing the 2018 National League Cy Young Award with a 10-9 win-loss record – but with two BJ scores in the 80s and 14 more in the 70s (click here for DeGrom’s 2018 game-log, noting that BJ Scores are denoted “GSC” for Game Score on the linked page).
Hence, we can “Kill the Win,” as MLB Network personality Brian Kenny advocates, with BJ Score providing an excellent substitute.
Alan Reifman is a Professor of Human Development and Family Sciences at Texas Tech University
