I only did a rollout here to get a better idea for the size of the error. Normally I'd take ++'s word for it and not care when it's this clear.
Why do I care about the size of it? Am I becoming a woman? No! Positions exactly like this one is where the relative strengths of the players have in my opinion a massive effect on what the proper cube action should be. A couple of characteristics that are most important in these types of positions are the fact that it's a recube instead of an initial cube and there are gammons floating around. Recubes + gammons have the potential to truly shorten a match. Instead of play 4 to 8 more games if we find a gammon on a 4 cube it's poof, match over. Even if no gammon still 4 points is a lot of point to bundle in one game in matches that are typically between 7 and 15 points.
When I was shown this cube I was basically told MCG sent over a great cube and got his opponent to take a bad cube. It's at this point I said "Did he really though?". I had the XG analysis in front of me so what was I talking about?
Well, this all hinges on MCG's opponent, Carl Sellars. I had never even heard Carl's name (sorry Carl) so a generally safe working assumption is if I haven't heard your name you at least play a 6 PR. I would later be told that Carl used to play back in the day and was a very good player. I was still waiting for someone to speak of Carl's current (or even former) playing strength as I've heard too many times "he is/was a good player" for me to watch and wonder if people are delusional or prefer being nice to reality. Nobody spoke up so I decided to at least put the match against MCG into XG and get a better idea.
The next question is, can we really get a reasonable idea of how Carl plays from just one match that is 9 games long?! A resounding yes! of course. It's not only the PR of a player if you watch the entire match, it's not even if they get the plays right or wrong, it's how fast they make the obvious correct plays, it's what plays they consider, it's what decisions they decide to use time on.
To cut to the chase on ++ with some selective rollouts of my own Carl played a 3.84 and MCG played a 3.49. If anyone would like the match file let me know here or by email or preferably both as I don't pay much attention to emails these days. I will be pulling positions and more from this match in the upcoming week.
A GNU rollout using the jac100 table for uneven players has this decision as a dead borderline take/pass decision. This starts to give us a bit of an idea at least what we could be doing given a certain PR difference. I know OtB if I played a 3 and my opponent played a 6 or worse I may not have cubed here. The higher their PR the more likely I'd be not to cube. (unless I figured they were passing of course)
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| XGID=aaa-BBC-C---bC----bbbbbB--:1:1:1:00:5:11:0:15:10 | |||||
| Blue on roll, cube action? | |||||
| Analyzed in Rollout | No redouble | Redouble/Take |
| Player Winning Chances: | 54.65% (G:21.52% B:1.43%) | 54.86% (G:22.14% B:1.41%) |
| Opponent Winning Chances: | 45.35% (G:14.77% B:1.87%) | 45.14% (G:15.72% B:2.72%) |
| Cubeless Equities | +0.238 | +1.173 |
| Cubeful Equities | ||
| No redouble: | +0.894 (-0.106) | ±0.010 (+0.884..+0.904) |
| Redouble/Take: | +1.173 (+0.173) | ±0.016 (+1.157..+1.188) |
| Redouble/Pass: | +1.000 | |
| Best Cube action: Redouble / Pass | ||
| Rollout details | ||
| 1296 Games rolled with Variance Reduction. Dice Seed: 39516723 Moves: 3-ply, cube decisions: XG Roller | ||
| Double Decision confidence: | 100.0% | |
| Take Decision confidence: | 100.0% | |
| Duration: 5 minutes 04 seconds | ||