In which we analyze MJP with some serious number crunching

Facts may be helpful in making decisions.

I am a strict constructionist when it comes to MJP. I am the Scalia of mutuality. I will always put in a mutual pairing before a non-mutual pairing. Further, I concentrate entirely on teams still in competition, working up from the bubble. The more in danger you are of not advancing into elims, the more I concentrate on getting you your best match. When it comes to getting a 1-1 for a team in competition vs a team that cannot break, the 1-1 goes to the in-competition team. I have, of course, written about this at great length here and on the NDCA site.

Among the tournaments I tabbed this year with MJP, using first TRPC and then tabroom.com (which does a better job with mutuality), are Yale, Bronx, Princeton and Columbia. These 4 tournaments add up to 2928 prelim rounds of Varsity LD. All were divvied up into 6 tiers, 18% each of the first 5 and 8% strikes. They were all large to very large fields, with pools hovering around 50% of the size of the field.

Remember: strict construction. Mutuality first.

Of the 2928 rounds:
2538 were 1-1. That is, 87%.
132 were 2-2. 5%.

This means that 93% were 1-1 or 2-2.

4% were 3-3. This means that 97% were 1-1, 2-2 or 3-3.

2% were 4-4; 1% were 5-5; 2% were 1-offs (usually 1-2, maybe lower); 1% were 2-offs (or worse). The percentages are rounded up, so in fact, this last 6% is probably more like 5%.

Important note: Easily half of the “bad” pairings (3-3 or worse) are the result of teams’ being out of competition. The most egregious pairings are desperation ballot pushes, for which no system can be held accountable.

Minor note: Making it 6 equal tiers (more strikes) would have little statistical impact.

Bottom line: going by strict mutuality and 6 traditionally divided tiers, MJP delivers better than 93% 1s and 2s in all in-competition rounds.

The raw data are at http://www.jimmenick.com/vault/mjp_breakdown.xlsx .