The Big Plays and Players of the NL Championship Series

Championship Win Probability

The first time Arizona had the overall lead in the series was not until Game 7, when Christian Walker’s groundout scored Corbin Carroll. The team was 1-0 up with the series tied 3-3, and it was the first time their series win probability had climbed over 50%. They had fallen below even after in the first inning of Game 1, as Zac Gallen allowed two home-runs, and had been playing uphill baseball since then. But as the old saying goes, it’s not how you start that matters, it’s how you finish. For it was the Diamondbacks who ended up reaching 100% for both Game 7 and therefore the Championship Series. The chart below shows how things ebbed and flowed over the seven games.

You can see that the first two games were almost all trending heavily towards Philadelphia, as you would expect. At the end of Game 1, the D-backs were down to a 34% shot at winning the series, and by the time they had fallen two games behind the following night, they had only a 19% chance of coming back. Things reached their nadir in the top of the seventh inning of Game 3. Philadelphia had just scored the first run of the night on Ryan Thompson’s wild pitch, and Arizona’s CS probability was down to 16%. That was matched in the late innings of Game 4: while the Phillies had a bigger lead in that game, they were only 2-1 up, rather than 2-0, which muted the impact.

But Arizona came back and took both. leveling the series. Game 5 went to Philadelphia, and dropped our chance down to 22%. But Arizona won as the series returned the East coast, setting up a pivotal Game 7. You won’t be surprised to learn that, at the series level, many of the most pivotal plays came in that contest. In fact, of the ten plays which changed the series probability the most, no less than eight were in Game 7; the other two were in Game 4. The biggest was in favor of the Phillies: Bryson Stott’s go-ahead RBI double in the fourth, was worth +7.02% on the Phillies’ World Series chances. The next most key play that night was Corbin Carroll’s game-tying single shortly thereafter, at +6.31% for Arizona.

Splitting those apart, we have to go back to Game 4, and what probably “feels” like the play which turned the series. That would be Alek Thomas’s game-tying two-run homer. In terms of single-game Win Probability, that was indeed the biggest of the series. It had a whopping +36.4%, rescuing the D-backs just when it seemed that they would be falling 3-1 down in the series. But in the larger context of the series, it didn’t take place in an elimination game, which reduces its importance at the series level. Still, it added +6.69% to the D-backs’ World Series percentage, which is no small figure. Gabriel Moreno’s go-ahead RBI later on was the other non-Game 7 play to make the series Top 10, coming sixth at +5.05%.

Game Win Probability

But if we do look at single-game Win Probability, the narrative changes totally. Nothing from Game 7 reached even +15% - the Stott double was the biggest at +14.0%. There were eight which were more significant than that, to their individual contests. But these were not evenly spread across the seven games. In fact, all of them came either in Game 3 or Game 4. The former, in particular, had six plays which swung fortunes by more than fifteen percent. Game 4 had the two addressed above. The rest of the series? None at all. Here’s a full list of the most significant plays in each game, by Win Probability:

• Game 1, +10.2%. Top 7, down 2-5: Gabriel Moreno, Fielder’s Choice P; Christian Walker to 3B on E1; Moreno to 1B
• Game 2, +10.0%. Bottom 1, tied 0-0: Trea Turner HR off Merrill Kelly
• Game 3, +25.3%. Bottom 7, down 0-1: Lourdes Gurriel Jr, RBI double, Alek Thomas scores
• Game 4, +36.4%. Bottom 8, down 3-5: Alek Thomas HR, Lourdes Gurriell scores
• Game 5, +10.2%. Top 1, tied 0-0: Bryson Stott RBI single, Bryce Harper to 3B
• Game 6, +11.3%. Top 3, up 3-1: Ketel Marte, RBI triple
• Game 7, +14.0%. Bottom 4, tied 1-1: Bryson Stott RBI double

Most Influential Players

What do we get if we tally up the numbers for our position players across the whole seven games? Who would win the MIP Award for Arizona this series? Turns out the answer is not Ketel Marte, but Gabriel Moreno - and he comes out top regardless of whether you use Win Probability or Championship Probability. His numbers there were +48.3% WP and +11.82% CP respectively. Marte was second by WP at +34.5%, but Corbin Carroll’s sterling performance in Game 7 allowed him to overtake Ketel in CP, with Carroll adding +6.83% compared to Marte’s 5.08%. At the other end... Evan Longoria and Emmanuel Rivera occupy the bottom two spots: Longo was last in CP (-8.62), while Rivera was worst in WP (-47.1%).

Below is a chart showing the Win Probability for all the Arizona position players in the series, from top to bottom.

We can do the same for our pitchers, and hand out a Most Influential Pitcher honor. Again, we have a consensus winner, who at least ties atop the chart in both WP and CP. The award goes to... Kevin Ginkel. He and Paul Sewald were level for Win Probability, both coming in at +42.0%. But the Gink-meister (Ginkinator? Gink-Emperor of Dune?) had a clear edge in CP, with almost half as much again as Sewald - his stranding of the tying run on base last night proved decisive. He racked up a startling 15.91% CP, with Sewald a still respectable 10.07%. At the other end... Well, let’s just saw Andrew Saalfrank should count himself lucky to be playing in the World Series!

Here’s the same chart, showing the Win Probability for our pitchers.