SideshowBob wrote:NugzHeat3 wrote:Pretty sure the plus-minus rating McCallum referred to is a completely different stat.
Sitting in his office in the Forum one day not long ago, Riley glanced at a computer printout that listed a "plus-minus rating" (a statistical analysis made by the Lakers' staff that covers everything from points scored to fouls committed) for every player in the NBA. The Chicago Bulls' Michael Jordan was on top with a .770 rating, Boston's Larry Bird was second at .700 and Johnson was in third place at .680.
"Last year Earvin was about .765, and I thought he'd play at that level this year, too," said Riley. "Last season he was a driven player. He was driven to win the MVP award and finally get his due. Because he's not a selfish player, it was hard for him, but he did it. He did it by constantly pushing himself to shoot, to penetrate, to take over a game. This year, for whatever reason, he hasn't done it. Maybe he's taken it upon himself to develop Byron. Maybe there's another reason. But I'd like to see him get that .765 every night."
http://sportsillustrated.cnn.com/vault/ ... /index.htm
I would have loved to see the details behind this metric.
I looked into this a bit and it seems like a fairly basic metric devised from box score numbers. Just adding all the positives (pts, asts, etc) and subtracting all the negatives (tos, missed shots, etc).

I do believe they have kept plus/minus numbers over the years as well though.
I came across this SI article dating back to 1998 touching on the increased reliance on advanced numbers, cyber scouting etc. They do mention keeping track of plus/minus numbers with an example below. As a side note, the entire article is a great, albeit fairly long read so make sure you check it out if you have the time or patience to go through it. Some interesting info in there on player tendencies, how statistical analysis helped the teams etc.
Seattle SuperSonics coach George Karl knew he liked having veteran guard-forward Nate McMillan on the floor, even though McMillan's statistics often were pedestrian. An analysis showed that McMillan's plus-minus rating (how many points an opposing team gained or lost with him on the court) was tops on the Sonics last season.
http://sportsillustrated.cnn.com/featur ... uting.htmlThere is an issue though, since the above quote doesn't match the data on nba.com. Schrempf, Payton and Hawkins are all ahead of McMillan in the plus-minus column for the 1996-97 season.
http://stats.nba.com/leaguePlayerGenera ... tOrder=DESAnother article below mentioning that LA did keep track of plus/minus numbers for certain players. This is obviously points for and against the team when those players are on court which is different from the plus-minus rating system that McCallum was referring to. Once again, the entire article is a pretty good read.
ONLY SO MUCH FITS IN BOX SCORE : Defense Left Out : Michael Cooper, Other Specialists Are Overlooked
May 16, 1985|SAM McMANIS | Times Staff Writer
The standard National Basketball Assn. box score, required reading for almost all players, seemingly provides enough pertinent statistical information to satisfy anyone.
It chronicles, in detail, everything from field-goal percentage to blocked shots to assists to offensive and defensive rebounds. But that doesn't tell Laker guard Michael Cooper, voted onto the NBA's All-Defensive team the last two seasons, what he really wants to know about the game. If Cooper could devise his own box score, one emphasizing defensive skills, it would include a wide range of categories, some rather unusual.
"They should come up with a statistic for taking the charge," Cooper said. "Call it CF (charging foul) in the box. It takes a lot of guts to step in front of Charles Barkley or Moses (Malone). You also should have a stat called FB--floor burns."
Cooper, of course, realizes that such unconventional statistics will never appear in any NBA box score. But he believes that there should be some tangible way to gauge the expertise of such defensive specialists as Boston's Dennis Johnson, Milwaukee's Sidney Moncrief and Utah's Mark Eaton.
"Defensive players are like garbage collectors," Cooper said, laughing. "You don't notice them unless they don't do their job. You handle the messes and the stinky stuff. Defense is dirty work."
Too dirty, or maybe just too unappreciated, to appear in a box score. Steals and blocked shots are the only two official NBA statistics that deal exclusively with defense, but those are not accurate barometers in determining which players are the most skilled defensively.
The pursuit of judging individual defensive skills has led many NBA teams to devise statistical systems. The Lakers, for instance, keep charts focusing on the players' \o7 effort \f7 in offensive and defensive rebounding, and have others that emphasize areas such as steals, forced turnovers and limiting an opponent's number of layups. They also have plus-minus ratings--points for and against the team when certain players are on the court.
But Coach Pat Riley said that finding statistics to judge individual defensive performance is very difficult.
"We're trying to come up with a scheme about how we can determine effort on defense," Riley said. "We've tried a few things, but it's hard to chart. You've got guys helping in the lane and things like that. We play such a switching, man-to-man defense that the responsibility, individually, is more to the team. We haven't come up with a fool-proof way." Richard Steinlauf says he has found a way. Steinlauf, a securities analyst for First Investors Corporation in New York, has developed what he calls a defensive box score, which basically is a complete reversal of a standard box score.
Using the teams' individual defensive assignments, Steinlauf's system provides a defensive field-goal percentage, based on the shots attempted and made against a player. There also are categories for defensive free-throw percentages, reverse figures on rebounds and turnovers, and a plus-minus category similar to the one used by the Lakers.
Again, based on the individual's defensive assignment, Steinlauf also charts the points per minute for and against a player and points per game for and against.
In short, there are enough statistic breakdowns to make any statistician ecstatic.
"What I do during a game is keep an alignment chart by jersey number," Steinlauf said. "It wasn't something I could do easily at first, but with practice, anyone could do it. I think the sport has a statistical gap when it comes to defense. My system is something that can be used by the league, the individual teams or the media."
So far, though, the NBA and its teams have expressed little interest in adopting Steinlauf's system. He has approached several newspapers with his system and traveled from New York at his expense to chart the Lakers' playoff series with Portland.
During the series, Steinlauf contacted Portland Coach Jack Ramsay, who did take time to briefly study the system.
"I'm surprised he didn't contact \o7 me\f7 ," Riley said. "People will send me all sorts of computer systems that rate players. All these systems are broken down from the box score and you just can't judge accurately from that."
Riley immediately found a major flaw in Steinlauf's defensive box score. Basically, Riley said the Lakers switch defensive matchups with such regularity that it would be nearly impossible to chart individual assignments.
Riley offered the following scenario:
"Let's say a Portland player drives to the basket and the guy guarding Jim Paxson does his job and drops into the lane to help out and stop the drive. The player then kicks the ball to Paxson for an open jumper. Who's to blame for the basket? It's usually the guy playing the ball, not the guy playing Paxson. The guy playing Paxson was doing his job, but this chart would put the blame on him."
Steinlauf admits his system is somewhat subjective.
"But it's the best way I've seen to chart one-on-one matchups," he said.
Steinlauf's defensive box score from the five-game playoff series between the Lakers and Portland provided some interesting and puzzling statistics.
For instance, Portland's Kiki Vandeweghe, strong offensively but weak defensively, was clearly a liability in the series, according to Steinlauf's statistics. Although Vandeweghe shot 50% from the field, the Lakers he was guarding shot 57%. He averaged 19.8 points a game, but gave up 17.8 points. In rebounding, Vandeweghe had only 11 and his opponents had 29. His overall plus-minus figure was minus 79.
Michael Cooper's impressive defensive skills were evident in Steinlauf's figures. Opponents shot only 35% against Cooper and he gave up only 10.2 points a game. But he had 13 turnovers--seven in Game 4 in Portland--and forced only seven in five games.
More than any other of Steinlauf's statistics, Riley took exception to the ones concerning Magic Johnson. According to Steinlauf, the players guarded by Johnson scored 102 points for a 20.4 average.
"He (Steinlauf) doesn't know where we are coming from with Magic," Riley said. "We almost have Magic as a roamer, a free safety. We put him on the point guard most of the time. We had him on (Portland's Darnell) Valentine. We told him to play Valentine only from 17 feet on in. His responsibility was to entice Valentine into shooting the ball.
"Secondly, once Valentine gives it up to a post player, Magic goes and doubles wherever he is. So, that let's Valentine roam free, but Magic is doing his job. You can't chart us like that because we're always trapping or switching.
"This is all too subjective. Kareem (Abdul-Jabbar) may block five shots but he changes the direction of five other shots. To me, that's as good as a block. A guy forces a turnover but the guy who picks up the ball gets the credit for the steal. Who should get credit? Maybe each should get half."
Although Cooper appreciates the efforts of those trying to give defensive players credit, he is wary of the defensive box score.
"If you get into all this, you may have too many stats."
http://articles.latimes.com/1985-05-16/ ... ox-score/2