Forum Archive : GNU Backgammon

MWC versus Equity (EMG) From:   Ken Address:   none Date:   24 April 2005 Subject:   Gnu MWC vs Equity Forum:   GammOnLine I have always used the MWC setting in GNU to analyze matches. A friend has recommended that I do not use it and look at equity instead. His reasoning is: "I've noticed a few times on GammOnline that you look at your gnu rollouts with MWC rather than money equity. I used to do this as well, but someone suggested I change, saying "why let the same move some time be a 2% error and sometimes an 8% error depending on the score." At first I was skeptical but switched and am VERY glad I did. I think you get a much more consistent view of correct checker play and can later adjust for match score if necessary. Try it, I think you'll like it." The reason that I have always used MWC for matches comes from my reading of http://www.bkgm.com/gnu/AllAboutGNU.html#game_record Quoting from there: "You may also prefer to see the Match Winning Chances of the moves instead of the equity. This shows the chances of winning the match as opposed to the evaluation according to a single game. To do so, press the MWC button:" Because I am interested in winning the match much more than winning a game, I choose to look at MWC. Also, I thought that if Gnu was looking at a single game, I would miss my mistakes in gammon go and gammon save situations. However, this does not seem to be the case. It seems that the moves are always ranked the same in either setting. Which setting do people use and why? Do you use one or the other based on a situation? /ken Robert-Jan Veldhuizen  writes: If GNUBG plays a match and you set it to display equity instead of MWC, it uses EMG, which is Equivalent Money Game equity. This is not the same as simple money equity; it allows for the matchscore. With EMG, a win on the current cube value is still +1 and a loss -1, however gammon wins or losses may not be +2 or -2, idem for backgammons and doubled games, etc. This is because of the different gammon values. GNUBG calculates all these using MWC. What's important to understand is that EMG and MWC are lineary related, so rankings will always be the same, and various differences between plays will be in the same proportions. I find EMG to be far superior for learning purposes. It's very hard to get a feel for MWC at all sorts of different scores. Also, it's much easier to see where one stands with the cube, since passing always means -1 and cashing +1 with EMG. I only use the MWC button sometimes to see how much MWC % is at stake in the current game, like: how much more important is the 3-away 2-away game, center cube, compared to the first game in a 11pt match. HappyJuggler0  writes: I always use equity but I started with MWC. Then one day I was dumbfounded by how badly a particular move was. I posted it on another forum and discovered that my problem was that I was treating MWC the same regardless of score, while with equity you don't have that problem. (The move was rather bad in equity too by the way lol). MWC misleads you into thinking a misplay of 53 on the opening roll in an 11pt match at 0-0 is much less of a problem than it is at 10-10 in the same match. Pretty much the same error (except for gammon implications) but radically different numbers. This skew based on score makes it much harder to detect recurring "types" of big mistakes since the numbers keep changing on you. But if yyou are on the bar and roll 61 and keep seeing that 8/2 is roughly the same blunder it tends to stick in your mind after a while and you can adjust the way you play. It is also extremely useful for cube purposes. By seeing the cube "problem" in terms of 1.000 (cubeful) and by seeing so many analyses I got much better at my cube skills at a rather quick rate. Just remember that the match score does affect things and you need to cube earlier with a match deficit etc. Once I made the switch to equity and once I got used to the new numbers never looked back.   Did you find the information in this article useful?           Do you have any comments you'd like to add?

 

GNU Backgammon

Analyzing GamesGrid matches  (Roy Passfield, Dec 2001) 

Batch analysis tool  (Øystein Johansen, June 2004) 

Cache size  (Ned Cross+, Mar 2004) 

Compiling for Windows  (Øystein Johansen, Jan 2002) 

Edit mode removing checker from bar  (Scott Steiner+, May 2003) 

Entering an annotated match  (Albert Silver, Dec 2003) 

Error rates: Gnu vs. Snowie  (Raccoon, Mar 2006) 

Even-ply/odd-ply effect  (Raccoon, Nov 2004) 

Even-ply/odd-ply effect  (Tom Keith+, Oct 2003) 

Even-ply/odd-ply effect  (Scott Steiner+, Dec 2002) 

Filter settings  (Robert-Jan Veldhuizen, Nov 2004) 

Gnu 0.13 versus Jellyfish and Snowie  (Torsten Schoop, Aug 2003) 

Gnu 0.13 vs. Snowie 4  (Albert Silver, June 2003) 

Gnu 0.14 vs. Jellyfish  (Michael Howard+, July 2003) 

Gnu versus Snowie and Jellyfish  (Michael Depreli, Oct 2005) 

How luck factor is calculated  (Gregg Cattanach, Aug 2002) 

How rollouts work  (Gary Wong, July 1999) 

How to enter an illegal move  (Øystein Johansen, Aug 2003) 

Importing .gam files  (PAR+, Mar 2005) 

Importing PartyGammon matches  (rew+, July 2006) 

Improving your game using GnuBG  (D.U.G.+, Nov 2002) 

Installing on Windows  (maareyes, Oct 2001) 

Interpreting JSD's  (Adrian Wright+, Feb 2005) 

JSD's and confidence intervals  (Daniel Murphy+, Jan 2005) 

Logging rollouts  (Øystein Johansen, Oct 2004) 

Luck rate  (Kees van den Doel+, May 2002) 

MWC versus Equity (EMG)  (Ken+, Apr 2005) 

Manually entering first roll  (Andreas Graf+, Apr 2005) 

Match equity tables  (Raccoon, July 2005) 

Personal reflections  (Louis Nardy Pillards, Sept 2002) 

Playing two computers against each other  (Stanley E. Richards+, Mar 2008) 

Python scripting  (Øystein Johansen+, Nov 2004) 

Quasi-random dice in rollouts  (Ian Shaw, Mar 2004) 

Question marks in game list  (Jim Segrave, July 2005) 

Questions and answers  (Jim Segrave+, Jan 2003) 

Questions and answers  (Jørn Thyssen, Aug 2002) 

Restarting a rollout with different settings  (Jim Segrave, Apr 2005) 

Restarting a rollout with different settings  (Robert-Jan Veldhuizen, Apr 2004) 

Rollout settings  (geoff arnold+, Apr 2007) 

Rollout settings  (Stick+, Nov 2005) 

Rollout settings  (Robert-Jan Veldhuizen, Mar 2004) 

Rollout settings  (Ian Dunstan, Aug 2003) 

Rollout settings for the impatient  (Robert-Jan Veldhuizen, June 2004) 

Running rollouts in background  (Bruce+, Apr 2004) 

Saving rollout results from command-line interface  (Jeremy Bagai+, Apr 2006) 

Saving rollouts  (Mislav Radica+, May 2006) 

Setting GnuBG's playing strength  (JP White, Sept 2001) 

Setting skill level  (Jim Segrave, Apr 2004) 

Setting up and saving a rollout  (Albert Silver, Dec 2003) 

What's GNU?  (Gary Wong, Oct 2001) 

Which player is player 0?  (Neil Kazaross+, Oct 2004) 

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