tag:blogger.com,1999:blog-7193007137551439191.post6202121631204899041..comments2023-12-27T18:04:21.987-05:00Comments on From Old Virginia: basketball mathitudeBrendanhttp://www.blogger.com/profile/10506945153264825303noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-7193007137551439191.post-42661748244394088212011-02-21T09:05:04.718-05:002011-02-21T09:05:04.718-05:00A steal ends an average possession, not a successf...A steal ends an average possession, not a successful one. Sometimes when you steal the ball, you've ended a possession that wasn't going to result in points anyway. The other team was going to miss the shot, dribble it off their foot, or throw an errant pass. And sometimes when you steal the ball, you've ended a possession that *was* going to result in points. On average, those two binary outcomes work out to ~1 point per possession ended by steal.<br /><br />I won't belabor the point further, because after all, we just swept VPI and ruined their NCAA bid, so what else matters, really?Davehttps://www.blogger.com/profile/13813445990225145593noreply@blogger.comtag:blogger.com,1999:blog-7193007137551439191.post-32729992053060580422011-02-18T23:04:16.399-05:002011-02-18T23:04:16.399-05:00Well, look at it this way: If I'm overcounting...Well, look at it this way: If I'm overcounting both steals and blocks, then the replacement-level number of 2.45 is also too high. If I were to cut the value of steals and blocks in half, I'd also have to cut the replacement-level value in half for the same reason, and I'd end up with the same multiplier.<br /><br />Anyway, maybe this is a better explanation. The <i>average</i> possession is one point because a <i>successful</i> possession is two points. A steal prevents the offense from having a successful possession, not an average possession. Therefore it's worth two points. A block is half a steal because the offense recovers half the time.<br /><br />The time to apply the logic that taking away a possession results in taking one point off the board is in a situation where you prevent the possession from ever happening in the first place - such as by slowing the pace down. Once the possession has begun, the outcome is assumed to be binary - either zero or two.Brendanhttps://www.blogger.com/profile/10506945153264825303noreply@blogger.comtag:blogger.com,1999:blog-7193007137551439191.post-23747521842158026812011-02-18T18:26:51.204-05:002011-02-18T18:26:51.204-05:00"The average team offensive rating is about 1..."The average team offensive rating is about 101, so essentially, teams average a point per possession. Possessions are, most of the time, either two or zero points, though. One point is about as common as three. So when you come up with a steal, you took two points off the board."<br /><br />I don't follow this logic. A steal takes away a possession; a possession is worth 1 point, on average; therefore a steal takes one point off the board, not two.<br /><br />True, few possessions end in exactly one point, but we're dealing in averages. So in short, you're over-counting steals (and blocks).<br /><br />If you want to not recalculate your metric (and I wouldn't blame you), leave it the same but argue that: "Every steal is itself worth ~1 point, but a steal is also strongly correlated with not-directly-measurable strong defensive play (which results in forcing bad shots, etc.). To give credit for that defensive play, I'll just apply a 2x multiplier to steals." Similarly for blocks.<br /><br />Overall, I do like your improvement on the metric -- I just want it to be better justified...Davehttps://www.blogger.com/profile/13813445990225145593noreply@blogger.comtag:blogger.com,1999:blog-7193007137551439191.post-34994771760838177112011-02-18T04:21:42.632-05:002011-02-18T04:21:42.632-05:00Looking at Akil Mitchell's two negative rating...Looking at Akil Mitchell's two negative ratings certainly makes me feel better about leaving James Johnson's redshirt in place.Anonymousnoreply@blogger.com