Difference between revisions of "Lafer number"

Latest revision as of 15:02, 1 June 2025

The degree of separation is a way of representing how connected quizbowl players are, similar to Bacon numbers in film or Erdős numbers in mathematical publishing. To qualify as a degree of separation, two players need to play on the same team together (whether middle school, high school, college, or open) in a quizbowl tournament, particularly if statistics from that tournament can be found in the HDWhite Database.

How to calculate

Ryan Rosenberg has assembled a graph database of players on his College Quizbowl Stats website (available as a file on the Quizbowl Discord server) that can be used to help calculate degrees of separation for College and Open events. For high school and middle school, however, degrees must be found manually through looking at the databases on HDWhite, NAQT, and College Quizbowl Stats. The list of players with a Lafer number of 1 (seen below) can be used as a centerpiece for calculations.

Lafer number

One method of measuring centrality in quizbowl is the Lafer number, calculating how many degrees of separation a player is from Matt Lafer (a longtime quizbowl player who has played in many open tournaments). The following is an example of how a Lafer number is calculated:

#	Name/Played with
0	Matt Lafer
	played Cambridge Open UIUC 2018 with
1	Halle Friedman
	played NASAT @ Columbia 2024 with
2	Noah Chen
	played 2025 ACF Regionals with
3	Olin Bose

Lafer numbers can potentially be used as a centerpiece to connect a pair of different players. Matt Lafer is the only player with a Lafer number of 0, and anyone who is disconnected from him entirely in databases (such as Ken Jennings, who has statistics for only one tournament and his teammates did not play any others), has a Lafer number of infinity. Other suggested centers include Mike Bentley and Matt Bollinger, both of whom have a Lafer number of 1. The following list is of all players who have a Lafer number of 1, as of May 27, 2025.

Players with a Lafer number of 1

Ezequiel Berdichevsky

Other Lafer numbers

2

Iain Carpenter (played with Mitch McCullar at 2024 COOT Online)
Jeff Hoppes (played with Selene Koo, Andrew Hart, and Seth Teitler at 2011 Chicago Open)
Matt Jackson (played with Matt Weiner and John Lawrence at 2014 Chicago Open)
David Madden (played with Matt Weiner at 2012 Chicago Open History Doubles)
Liam Starnes (played with Conor Thompson and John Lawrence at 2022 CMST II)
Forrest Weintraub (played with Mitch McCullar at 2024 COOT Online)
Andrew Yaphe (played with Selene Koo and Seth Teitler at Chicago at 2005 ICT and others)
Charles Young (played with Conor Thompson at 2020 SUN Open)
Andrew Zeng (played with Mitch McCullar at 2024 COOT Online)

A list of players with Lafer numbers of 2 and greater (only on College Quiz Bowl Stats) is available as a .csv file created by Ryan Rosenberg.

Theory

"Pockets"

While most college and open players frequently have low separation from each other, or Lafer numbers, the Lafer numbers can become a lot higher in high school and middle school levels. While the fact that there is (usually) continuity between players over the years as older players play with younger ones, the only way they get Lafer numbers is by those players that either choose to play at NASAT or open tournaments, or choose to continue doing quizbowl in college.

For example, Mountain Lakes High School (and its middle school counterpart Briarcliff) have had a quizbowl program running since 2011 and has had over 100 players over the years. However, as only five of them have gone on to play in college (and three of them have a known Lafer number of 3), every other person who has played for the high school has a Lafer number of four or above.

#	Name/Played with
0	Matt Lafer
	played ACRONYM 2017 with
1	Eric Mukherjee
	played 2024 NASAT Online Open with
2	Jason Golfinos
	played 2014 ACF Regionals with
3	Ted Rappleye

#	Name/Played With
0	Matt Lafer
	played Scattergories 5 (2021) with
1	Anderson Wang
	played 2024 Chicago Open with
2	Emmett Laurie
	played 2018 ACF Regionals with
3	Ron Mucci