I have some bigger thoughts on the Trent Richardson trade, but I want to first address a statistic I’ve seen cited frequently the past few days. You’ve probably heard some variation on the following, perhaps first reported by ESPN:

Since the start of 2012 with Richardson on the field, Browns quarterbacks were sacked on 4.8 percent of dropbacks. With Richardson off the field, Browns quarterbacks were sacked on 9.4 percent of dropbacks.

Colts quarterbacks have been sacked on 6.2 percent of dropbacks since the start of last season, the ninth-highest rate in the league.

I’ll assume the numbers are accurate, but stats like that don’t mean anything out of context. The conclusion isn’t spelled out, but the reader is asked to connect the dots: Richardson is good at pass protection and Indianapolis could use an upgrade in that department, so this is another reason to like the trade for the Colts. But when is Richardson most likely to be off the field? In obvious passing situations, which happens to be the most likely time the Browns would be sacked.

Brandon Weeden and other Cleveland quarterbacks were sacked 36 times last year and 11 times in the first two games of 2013. First, we should note that Thaddeus Lewis started in week 17 last year against the Steelers — his only start of the year, and the only game Richardson has missed in his pro career. He was sacked four times on 36 dropbacks, an 11.1% rate. So let’s throw that game out, since nobody cares about Lewis’ sack rate.

According to NFLGSIS, Richardson was not on the field for 22 of the 43 sacks of Browns quarterbacks over the last year and two games. But the fine print is the real story: only five of those 22 sacks came on 1st or 2nd down, only seven came when Cleveland had the lead, and only three of those sacks occured when the Browns needed fewer than seven yards for a first down. Take a look:

I’ll buy that Browns quarterbacks were sacked much less frequently when Richardson was on the field. But that’s because Richardson wasn’t on the field when the team faced 3rd and 19 trailing by two touchdowns, and it is impossible to deduct from this information that his presence (instead of another running back) would have changed the team’s fate on such a play.

Here’s another way to spin the numbers to imply that Richardson is a poor pass blocker: Cleveland quarterbacks were sacked thirteen times on 1st-and-10, and Richardson was on the field for eleven of them. That’s just as misleading, of course, because Richardson is usually on the field on 1st-and-10.

On average, the sacks without Richardson occurred on down 2.7, with 10 yards to go, and the Browns trailing by 5.3 points. With Richardson, the average down was 1.6, the yards to go was 8.5, and Cleveland trailed by 5.1 points. Reports are varied as to Richardson’s actual pass-blocking ability, but it’s pretty clear to me that you can’t judge him using a “with or without you” type of statistic. The fact that he was only on the field for two third down sacks — and both were on 3rd-and-1 — is probably more of an indictment of his pass blocking than anything else.

Pro Football Focus gave Richardson a -2.6 rating in pass protection last year, but that’s far less interesting than the other data they provide. According to PFF, Richardson was on the field for 725 snaps last year. The Browns passed on just 55.3% of Richardson’s snaps, compared to 92% for backup Chris Ogbonnaya. Despite being on the field for just 153 snaps, Ogbonnaya was in on 141 pass plays, compared to just 401 for Richardson. In other words, the Browns tended to replace Richardson with “silent G” in obvious passing situations.

Also of note: when Richardson was on the field on a passing play, PFF has him pass blocking just 17% of the time, while Ogbonnaya was blocking on 27% of his passing snaps. That doesn’t mean Richardson is a poor blocker — having him as a safety valve or running a route isn’t a bad idea or an indictment of his skills — but it does paint a picture of how Cleveland used him. The Browns deployed Richardson as a runner, and either took him off the field or had him as a potential target on most pass plays. That’s hardly the takeaway you would get, though, if you look at the Browns’ sack rate with and without Richardson. The real flaw is to use the “with or without you” sack nuumbers and imply that Richardson will help keep Andrew Luck’s jersey clean. Again, Richardson may or may not be great in pass protection — most of the folks I’ve spoken with say he’s average, and I don’t claim to have anything to add to that — but the Browns sack rate with him on the field is evidence of only one thing: Cleveland rarely asked him to pass block.