toddwschneider / matchplay

Match play scripts

Some assorted scripts in support of this post about match play golf:

How Many Paths are Possible in an 18 Hole Round of Match Play Golf?

• calculate_match_play_paths.R: backward induction to calculate the number of possible paths in a round of match play golf
• draw_match_play_tree.R: make pretty match play trees using ggplot2
• usga_data_analysis.R: some one-off analyses of the hole-by-hole USGA data used in the post
• usga_hole_by_hole_data.csv: the raw hole-by-hole data
• usga_match_data.json: JSON representation of each match
• usga_scraper.rb: quick and dirty script to collect data from the USGA's website for amateur championships from 2010-2014

matchplay's Issues

# and % of valid 18 character paths

Hi Todd,

A really cool analysis that combines my obsession for golf and statistics, although it would seem not quite to your level - the stats, don't know about your golf abilities, but almost certainly not to your level either!

I understand the logic behind calculating the approx. 170m total number of all valid paths, but confused by the implications of the approx. 132m 18 character paths. I interpret this to mean 78% of all matches will be decided on exactly the 18th hole, not before (of course ignoring unequal probabilities in reality for the three outcomes hole-by-hole). However, this seems counter-intuitive as, for example, in my own club's championships being played out now well more than half the matches have been decided before the 18th (including a diabolical 9 and 8 for one sorry loser!). Or have I misinterpreted something, especially given your next sentence that states 34.2% of all 18 character sequences are valid paths. But this is based on the approx. 387m paths of which more than half are invalid, eg "11 and 7", so don't understand what relevance the 387m has as a denominator in any calculation?

Hope to hear back.

Regards, Pete McMillen, Wellington, New Zealand.