SPC Analysis of MLB Home Runs

From the stepped control limits you can see when the “Babe” changed the nature of Baseball in 1921. The relative drought of home run production in the early 40s was no doubt attributable to WWII. Recently, power production was evident from Mark McGuire when he played for the Oakland A in 1995 & 1996.

The National League saw recent out-of-control points with the record pace of Barry Bonds in 2001. You can also see the effect Mark McGuire had in 1998 and 1999 on this chart with his joining the St. Louis Cards.

Charts generated by SPC IV Excel.

Here is a list of the top 20 home run seasons (by player) as measured by the percentage of at-bats which result in a home run. Production by McGuire, when he was healthy, appears “Ruthian” by this measure!

The Pareto Chart suggests the “Cinderella Story” only goes down as far as the 8th seed! The data shows that for the last 23 years 74% of the Tournament Champions were either a #1 or #2 Seed. Maybe you should look at your Tournament Pool choices again?

The total points scored in the Championship Game of the NCAA Tournament from 1939 to the present may show the possible effects of rule changes on scoring. The first process shift occurred in 1950, which coincided with the introduction of the "1 and 1" foul shot. Although this was the only rule change that year, it is possible that other factors may have also made a difference. Interestingly, the 45 second shot clock in 1985 may have corrected a decline experienced from 1979-84. The introduction of the 3 point shot in 1987 seems to have made little difference, at least in the short term, although it may contribute to the increased scores from 1993 to 2001 (as evidenced by the run test violation).

Learn more about the SPC principles and tools for process improvement in Statistical Process Control Demystified (2011, McGraw-Hill) by Paul Keller, in his online SPC Concepts short course (only $39), or his online SPC certification course ($350) or online Green Belt certification course ($499).