
Inspiration.
I very much enjoyed Jim McLennan’s The Arizona Diamondbacks Have Not Gone Streaking. I learned that the Diamondbacks have not won 7 consecutive games since 7 September 2017 (a very long time).
And I tip my hat to JWinMesa for his comment to that article. A summary is that as measured by Total Streak Quotient, TSQ (5 consecutive games won or 5 consecutive games lost), the Diamondbacks are one of the least streaky teams of the decade.
A Remarkable Discovery.
As I prepared my series preview for the Diamondbacks vs Royals (series starts 14 September) I compared the teams’ TSQ for this season. What was remarkable is that the Royals were twice as streaky (TSQ of .273 vs .133).
The TSQ calculation follows:
TSQ = (Streak Wins plus Streak Losses) divided by (total games).
My calculation for the Diamondbacks revealed something remarkable: This season, the Diamondbacks have not lost 5 consecutive games. That means no losing streaks happened.
Investigating That Discovery.
Come From Behind Wins. This season, 42 games (through 5 September) were won after the Diamondbacks were behind at some point in the game. That is exceptional!
Impactful Come From Behind Wins. This season, there were 21 come from behind wins with scores so close that the RBI event (while the Diamondbacks were behind, and that either tied or put the Diamondbacks ahead) was at least as large as the differential in the final score. That means that half the games would likely not have been won without the RBI event while the Diamondbacks were behind.
That kind of RBI event is precisely the type of event that prevented losing streaks. For example, in March/April, 13 of 16 wins were come from behind (8 were impactful come from behind wins). Without much doubt, a long losing streak would have happened except for the impactful come from behind wins.
The following table shows games with the impactful RBI, and the players who made the impact. In three impactful come from behind wins, I gave credit to two batters because it was the fair thing to do. Data from Baseball Reference.

UPDATE: On 9/6 against HOU, James McCann’s sac fly tied the game. The Diamondbacks won, so his RBI was the 22nd impactful RBI event (and the 43rd come from behind win). Honorable mention to Nolan Arenado whose 2-run homer put the Diamondbacks ahead the rest of the game.
Three Batters Had 52% of the Impactful RBIs in Come From Behind Wins: Vargas, Perdomo, and Marte. I looked at the batters whose RBI took the Diamondbacks from behind to either tied or ahead. In three impactful come from behind wins, I gave credit to two batters because it was the fair thing to do.
Explanatory why March/April had more come from behind wins. Both Vargas and Perdomo had an above average OPS in March/April (and no other months). That explains why March/April had twice as many come from behind wins as the other months. Also, every month had at least one of Vargas/Perdomo/Marte with an above average OPS.
An Explanation for Vargas and Perdomo having impact. When opponents’ pitchers have the lead, and pitch to batters with below average hard-hit percentages, they can get overconfident. They failed to consider that Vargas and Perdomo have stellar squared-up percentages (89th percentile and 96th percentile), which allow them to hit RBIs effectively in come from behind situations.
Although Ketel Marte had an above average hard-hit percentage, his hard-hit percentage was below averaeg in August. For the season, his squared up percentage was above average (62nd percentile). So the explanation somewhat applies to Marte, too.
Summary.
My calculation of Total Streak Quotient for the Diamondbacks revealed something remarkable: This season, the Diamondbacks have not lost 5 consecutive games. That means no losing streaks happened.
This season, 42 games (through 5 September) were won after the Diamondbacks were behind at some point in the game. Half of those wins ended with scores so close that the RBI event (while the Diamondbacks were behind, and that either tied or put the Diamondbacks ahead) was at least as large as the differential in the final score. That kind of RBI event is precisely the type of event that prevented losing streaks.
Three Batters had 52% of the impactful RBIs in come from behind wins: Vargas, Perdomo, and Marte.
Although Vargas and Perdomo had below average hard-hit percentages, their stellar squared up percentages combined with being underestimated by opposing pitchers, produced above-average impactful RBIs.





















