The record for most consecutive games versus over and under .500 teams

A guest post by Tom Ruane of SABR and Retrosheet

I thought it might be interesting to look at four groups:

1) under .400,
2) under .500,
3) over .500 and
4) over .600.

Here's what I found:

1) Starting on August 11, 1885, the Chicago White Stockings
played a record 23 straight games against opponents with
a winning percentage under .400. During the streak, they
played only Buffalo, Detroit and St. Louis. It ended when
they faced Boston (which entered the game with a
none-too-impressive winning percentage of .406). Chicago
went 20-2-1 during the streak.

The longest such streak since 1900 is nineteen and it was
done four times:

2) The Chicago White Sox played 51 straight games against
losing teams from May 27 to July 10, 1966. The streak ended
when they hosted the third-place Indians in the first game
following the All-Star break. Ironically, the Sox went only
22-28-1 while playing losing teams, and 45-32 afterwards.
No teams are close to their streak, the second longest
being a run of forty straight games by the San Francisco
Giants in 1986. It ran from July 3rd to August 17th and,
like the White Sox, the Giants had a losing mark (19-21)
while it lasted.

3) The top five teams with the most consecutive games
played against winning teams:

At the end of the streak by the 1916 Senators, the only
other team in the AL with a losing record was the 27-94
Philadelphia Athletics. And the three streaks from 1908 are
due to the practice of scheduling long road and home trips
between the eastern and western teams. In 1908, all of the
western teams had winning records.

4) The longest stretch of games against teams with a
winning percentage higher than .600 was 27 by the
Philadelphia Quakers in 1884. From May 20th to June 19th,
they went 6-21 against Boston, Providence and New York.
Entering the games of May 20th, those three teams had a
combined record of 37-5. Philadephia had been in fourth
place at the start but was in seventh place at the end of
the run.

The record since 1900 is 21, by the 1998 Tigers from
April 3rd (which was the first game of the second series
of the year) to 30th. Given how early in the season
it was, a few more wins here and there might have
short-circuited the streak, but Detroit went 5-16 in the
games.