Do home day games hurt the Cubs?

This post will look at the role night and day games play with respect to home field advantage. Over the years people have speculated that day baseball at Wrigley Field contributes to their perennial losing habits. Below are tables representing two different periods showing Chicago Cubs (CHN) win/loss percentages day and night versus league averages.

1989-2013

In this set of years the Cubs had night baseball but restricted.  The table below shows that throughout the league teams play 2/3 of their home games at night while the Cubs play a little over 1/4.  Although the Cubs are below average in both night and day home game winning percentage, they are below average in general with a 0.481 winning percentage.  The league total winning percentages are close enough to call it a wash between night and day home games.  Based upon the below winning percentages Cubs actually play better during home day games but this data pool isn’t deep enough to make that conclusion.

 NIGHT  #Games  DAY  #Games  %NIGHT
CHN 0.495 535 0.513 1463 26.8
TOTAL 0.538 39116 0.542 18595 67.8

1965-1988

In this period the Cubs didn’t play any night games except for a handful at the end of 1988 when they first turned the lights on at Wrigley in August of 1988. Here are the Cubs numbers against league numbers.

NIGHT #Games DAY #Games %NIGHT
CHN 0.500 6 0.522 1915 0.3
TOTAL 0.540 30002 0.534 16418 64.6

The above table also shows that winning percentages for home night games are equal to home day games. Thus, night or day, neither helps nor hurts the home team. In this period the Cubs only played day games (except the 6 in 1988). The Cubs 0.522 home day winning percentage is less than league average but the Cubs’ overall winning percentage of 0.478 during that time period is also less than league average.  Total league average winning percentage has to be exactly 0.500.

Conclusion

The data finds that based on league averages, day or night does not provided any advantage or disadvantage to the home team, the Cubs being no exception.