Last year, we added support for a slightly modified version of the Glicko-1 rating system and I posted a pretty thorough article about it here.
I proved a few things that I already knew, but most notably that it’d be more accurate to treat split decisions and majority decisions as draws, than to treat them as full wins. Prediction rates were highest when I assigned a win value (max=1.0) of 0.55 to split decisions and 0.61 to majority decisions. This means that the loser in these cases receives the remainder of the win value. The same thing very likely applies to close unanimous decisions, but we’ll keep it simple for now. For the record, in a draw situation, 0.50 goes to both fighters.
Disqualifications are another strange outcome too. After watching them happen in MMA, gut feelings tell you that in most cases, they are freak occurrences. We have to count them in the official results, because if we didn’t, fighters would use them to bail themselves out of bad situations unless thoroughly penalized. Unfortunately, there aren’t too many of them, which makes them a poor subject for analysis.
So, what happens if we run the rating system against the pro bout database where we treat split and majority decisions as draws and ignore DQs? Well, wonder no more!
| HW | |
| = | Stipe Miocic |
| = | Daniel Cormier |
| = | Francis Ngannou |
| = | Curtis Blaydes |
| +1 | Ryan Bader |
| -1 | Derrick Lewis |
| = | Junior dos Santos |
| = | Jairzinho Rozenstruik |
| = | Alistair Overeem |
| = | Alexander Volkov |
| LHW | |
| = | Jon Jones |
| +1 | Thiago Santos |
| -1 | Jan Blachowicz |
| = | Phil Davis |
| +1 | Glover Teixeira |
| +1 | Dominick Reyes |
| +1 | Ronaldo Souza |
| -3 | Vadim Nemkov |
| +1 | Anthony Smith |
| -1 | Corey Anderson |
| MW | |
| = | Israel Adesanya |
| = | Paulo Henrique Costa |
| +2 | Yoel Romero |
| -1 | Robert Whittaker |
| +1 | Gegard Mousasi |
| +1 | Jared Cannonier |
| +2 | Kelvin Gastelum |
| +2 | Jack Hermansson |
| +2 | Lyoto Machida |
| -2 | Darren Till |
| WW | |
| = | Kamaru Usman |
| = | Jorge Masvidal |
| = | Tyron Woodley |
| = | Colby Covington |
| = | Leon Edwards |
| = | Douglas Lima |
| = | Stephen Thompson |
| +1 | Gilbert Burns |
| -1 | Michael Chiesa |
| +2 | Nate Diaz |
| LW | |
| = | Khabib Nurmagomedov |
| = | Justin Gaethje |
| = | Dustin Poirier |
| = | Tony Ferguson |
| = | Charles Oliveira |
| = | Diego Ferreira |
| = | Dan Hooker |
| = | Kevin Lee |
| +1 | Paul Felder |
| -1 | Ben Henderson |
| FW | |
| = | Alexander Volkanovski |
| = | Max Holloway |
| = | Patricio Freire |
| = | Chan Sung Jung |
| = | Zabit Magomedsharipov |
| +1 | Frankie Edgar |
| +1 | Calvin Kattar |
| -2 | Josh Emmett |
| = | Lance Palmer |
| +1 | A.J. McKee |
| BW | |
| = | Henry Cejudo |
| = | Marlon Moraes |
| +1 | Jose Aldo |
| -1 | Aljamain Sterling |
| = | Petr Yan |
| +1 | Pedro Munhoz |
| +1 | Demetrious Johnson |
| -2 | Cory Sandhagen |
| = | Kyoji Horiguchi |
| = | Manel Kape |
| FLY | |
| = | Deiveson Figueiredo |
| = | Joseph Benavidez |
| = | Brandon Moreno |
| = | Alexandre Pantoja |
| = | Jussier Formiga |
| +1 | Alex Perez |
| -1 | Askar Askarov |
| = | Zhalgas Zhumagulov |
| +1 | Wilson Reis |
| +1 | Yunus Evloev |
| WFW | |
| = | Amanda Nunes |
| = | Cristiane Justino |
| = | Kayla Harrison |
| +1 | Arlene Blencowe |
| +1 | Felicia Spencer |
| -2 | Julia Budd |
| = | Megan Anderson |
| = | Larissa Pacheco |
| +2 | Sinead Kavanagh |
| -1 | Sarah Kaufman |
| WBW | |
| = | Germaine de Randamie |
| = | Holly Holm |
| = | Aspen Ladd |
| = | Irene Aldana |
| = | Julianna Pena |
| +1 | Sara McMann |
| -1 | Raquel Pennington |
| = | Sijara Eubanks |
| +1 | Bethe Correia |
| -1 | Macy Chiasson |
| WFLY | |
| = | Valentina Shevchenko |
| = | Katlyn Chookagian |
| +1 | Liz Carmouche |
| -1 | Jessica Eye |
| = | Ilima-Lei Macfarlane |
| = | Jennifer Maia |
| = | Roxanne Modafferi |
| +5 | Antonina Shevchenko |
| = | Vanessa Porto |
| -2 | Joanne Calderwood |
| WSW | |
| = | Weili Zhang |
| +1 | Joanna Jedrzejczyk |
| -1 | Jessica Andrade |
| = | Rose Namajunas |
| = | Tatiana Suarez |
| +3 | Claudia Gadelha |
| +3 | Cynthia Calvillo |
| -1 | Brianna Van Buren |
| -3 | Carla Esparza |
| -2 | Nina Ansaroff |
| WAT | |
| +1 | Ayaka Hamasaki |
| -1 | Seo Hee Ham |
| = | Jinh Yu Frey |
| +1 | Mina Kurobe |
| -1 | Viviane Pereira |
| = | Miyuu Yamamoto |
| = | Kanna Asakura |
| = | Ashley Cummins |
| +3 | Alesha Zappitella |
| = | Jeong Eun Park |
Doesn’t change all that much, does it? The biggest change is one you don’t see, seeing Rafael Lovato Jr. fall to #11 from #4.
The biggest % gainers out of all Top 50 currently ranked fighters were T. Santos (23.8%), Werdum (20.7%), Ducote (19.4%), Barboza (16.8%), Machida (15.1%), Pettis (15.0%). The biggest % losers are Lovato Jr. (-45.9%), Nemkov (-36.0%), Moraes (-31.1%), Ige (-30.4%)
Thoughts?