Does Scoring the First Run Make a Difference?

What common sense tells me.

Common sense tells me that scoring the first run should not matter for three reasons:

• Each team experiences the same number of outs unless they have won the game and are not allowed to continue sending batters to the plate. Because of that equality, batting first and thereby possibly scoring first should not matter.
• With a typical 9 innings per game, both teams have many chances to score runs after the first run scores.
• If all other things were equal, the team that bats in the top of each inning (the visiting team) is more likely to score the first run of the game. Yet it’s common knowledge that the home team has an advantage.

When the teams are unevenly matched, the better team will likely score many more runs, and they are the favorites to score the first run. However, that correlation does not mean that scoring the first run gave that team an advantage.

That is the interesting question, “Did scoring the first run provide an advantage to winning the game?”

This season, the Diamondbacks’ win-loss record was ranked in a tie for 29th/30^th. Therefore, saying that the Diamondbacks won games because of uneven team matchups is a weak argument. They are an ideal team to look at in determining whether scoring the first run provided an advantage.

For the Diamondbacks in 2021, let’s look at the data.

When the Diamondbacks scored the first run, it was significant.

In 2021, when the Diamondbacks scored the first run of the game they won 56.3% of their games (27 of 48 games). When the Diamondbacks did not score first, they won 21.9% of their games (25 of 114 games). This difference (56.3% vs 21.9% winning percentage) is huge and significant.

When they won the game, the first run was scored via homer in 29.6% of the games (8 of 27). Therefore, scoring the first run with non-homers was more significant than homers.

Looking at baserunners when the first run event happened, three players tied by being on base 7 times: Carson Kelly, Josh Rojas, and Christian Walker.

Runs in the first inning.

Historically speaking, in baseball the first inning has more runs than any other inning per this MLB article.

Although the Diamondbacks scored most of their runs in the first inning in 2018, in the three seasons since then other innings had the most runs.

The following table shows that for the Diamondbacks runs (RBIs) scored in the first inning dropped from 123 in 2018 to 90 in 2019 to 60 in 2021. In the context that total runs (RBIs) scored were higher in 2019 and about the same in 2021, that trend is very significant. I’m optimistic that trend can be reversed.

Diamondbacks. Data from Baseball Reference.

Let’s look at why reversing that trend is important.

When the Diamondbacks scored the first run of the game in the first or second inning it made a difference.

When the Diamondbacks scored the first run of the game in the first or second inning, they won 62.2% of games (23 of 37 games). When they scored the first run of the game in the third inning or later, they won 36.4% of games (4 of 11).

Interestingly, when the first run was scored in the third inning or later, there were four games where first score was a homer. The Diamondbacks lost all four games.

The following two graphs show types of scoring events and how often they happened in each inning. They include all scoring events, not just events that scored the first run of the game.

Diamondbacks, 2021 season. Data from Baseball Reference.

Diamondbacks, 2021 season. Data from Baseball Reference.

The importance of Plate Appearances.

Common sense tells me that scoring runs contributes to having more plate appearances (PAs). The following graph shows that for the Diamondbacks, plate appearances trended downward.

Diamondbacks. Data from Baseball Reference.

It is logical that if for an entire season the Diamondbacks had more PAs than the number of batters their pitchers face (BF), then they had more wins than if they had less PAs. Let’s look at a comparison of PAs and wins.

The following graph shows a correlation between (PAs-BFs) and team wins. For visual presentation clarity, it shows (actual wins minus wins to be a .500 team) multiplied by 10.

Diamondbacks. Data from Baseball Reference.

This correlation provides a unique method to predict the team’s wins at the end of the season. For example, looking at the differences between PAs and BFs from 2016 to 2021 my gut tells me (with an assumed season start of season on 1 April):

• PA-BF=+25 at end of April, predict 93 win season.
• PA-BF=+6 at end of April, predict 84 win season.
• PA-BF=+3 at end of April, predict 82 win season.
• PA-BF=-24 at end of April, predict 68 win season.

Summary.

When the Diamondbacks scored the first run of the game it significantly increased their winning chances. When games were won, about two thirds of first scoring events were non-homers.

The Diamondbacks have a three year trend of scoring less runs in the first inning. Their total runs scored in all innings was higher or about the same, while first inning production fell.

Scoring less runs in the first inning is a significant problem because when the Diamondbacks score the first run of the game, when they score that run in the first or second inning their winning percentage is nearly twice as high compared to later innings.

Scoring runs, especially the first run of the game, contributes to increased plate appearances. Comparing Diamondbacks’ plate appearances to Diamondbacks’ batters faced is positively correlated to team wins.