Analytics Audible: Contact Balance Index
What is Contact Balance Index? The name Contact Balance Index is a boring AI derived label for a pretty cool stat that should be called something like Grit-Factor or The Get-The-Fuck-Off-Me Gene. It's a rushing stat that looks at the relationship between A rusher's yards before contact and yards after contact. A rusher's yards before contact are mostly reliant on the team around him, specifically the run blockers. Yards after contact, however, are all based on the rusher's power, vision balance and fuckin grit when being hit. A high CBI tells you when a rusher is doing more after contact than before it and helps us identify the rushers that, while they may not be popping off the stat page, they are running hard and their poor stats are more of a reflection of the team around them than their skill/effort.
You can play with the table above if you're interested in how rushers performed in yards before or after contact last season, but right now I have it sorted by the CBI (which is just yards after contact divided by yards before contact). For more context here's the top ten above compared to the league average:
The standout here is Antonio Gibson, who had over four times the amount of yards after contact than before contact. To be honest, when doing this exercise, I had to remind myself what team he played for last season. He's been a bit of an afterthought, but that's unsurprising... he's ostensibly the backup running back on a Patriots team that was straight up bad last year (remember my DVOA rankings? Yeah the Patriots were ranked 30th in both offense and defense. So, at least they were balanced?). On top of that, he ran for 538 yards on 120 attempts for 4.5 yards per carry, one touchdown and 2 fumbles.
The thing is, he was the second worst running back in the league as far in yards before contact (0.858), meaning his team was not giving him space. This checks out because his teammate, Rhamondre Stevenson, was the 6th worst (1.2). But Antonio was first in the league for yards after contact with 3.65. So the guy just kept chugging, despite what was thrown at him. Meanwhile, Rhamondre still made our top ten (by virtue of having a dismal YBCO, but his YACO ranked #27 with 2.7.
What does this mean? This means that if the Patriots offensive line takes the leap they think it will take (they took Will Campbell 4th, after all) then we might should be seeing a significant increase in Antonio Gibson's production. Well, from both, really, but if both have the same increase in YBCO but Gibson's YACO is still superior, that will reflect in his production and more importantly, his fantasy football points... which will turn heads. This means he could be a valuable sleeper in fantasy this season (if Mike Vrable doesn't bench his ass for fumbling in week 1).
Another player that stands out on this list is Kenneth Walker. Remember how Antonio Gibson ranked second among running backs in YBCO? Well guess who was first? With a measly 0.824 yards before contact and an impressive 2.922 yards after, Kenneth Walker is another one who outperformed his stat line. Of course, it doesn't help that he missed six games, but he had 573 yards on 153 attempts for 3.7 yards per carry, 7 touchdowns and a fumble. Unfortunately, his career has kind of defined by injuries but... if he can stay healthy and if their offensive line improves, then he could be another breakout fantasy sleeper. Since it's August and by definition, all 32 offensive lines are better now than they were last year, I like those odds.
Again, it's no accident that Walker's teammate Zach Charbonnet is on this list too. But, similar to Rhamondre, he had more yards before contact, less yards after contact, and less yards per carry. The metrics combined tell a tale of Walker and Gibson being more efficient, despite having less fantasy points.
Another pair of running backs from the same team making this list are Tank Bigsby and Travis Etienne. According to the Jacksonville Jaguars depth chart on ESPN, Etienne is their starting running back, but the question is, for how long? Tank just outright outperformed Etienne last season with more carries, yards, yards per carry (duh), touchdowns, and yards after contact (despite having about the same yards before contact resulting in a much better CBI). According to PFF's fantasy rankings, Tank has an ADP (average draft position) of 113 while Etienne's is 115. Translation: when teammates are ranked next to each other it means that we don't know what to do with them (per the folks at the Ringer Fantasy Football Show). But I'm here to tell you that come draft day, and you're staring at both of them and you want one of them; take Tank.
Gus Edwards doesn't appear to be on a team right now. He was on the Chargers last season but was released in March in favor of Najee Harris. I like Gus Edwards but he was straight up out performed by J.K. Dobbins last season. If Edwards does get on a team this season, he's worth keeping an eye on but as far as fantasy goes, he's a non factor.
Ray Davis had an entire yard before contact less than his teammate James Cook and almost 3 whole yards less than his quarterback). Is that just due to the situations he was put in? Regardless, he led the team in yards after contact, hence his placement on this list. He simply was used less, carrying the ball almost half as much as James Cook, producing less than half the yards and three touchdowns to Cook's 16 (and Josh Allen's 12). So despite showing promise, there simply doesn't seem to be room in the Buffalo fantasy world for a RB2... but he would make an extremely valuable handcuff.
David Montgomery and Jahmyr Gibbs had almost the same exact yards after contact but Gibbs had significantly more yards before contact as well as yards per carry. Still Montgomery has proved himself a viable fantasy option if you miss out on his teammate in the first round. Will the loss of OC Ben Johnson change that? A lot of people seem to think so.
The last person in our top ten is Breece Hall. He had a down year last year but if you believe that Justin Fields will open things up for him, his ADP is down in the 50's. I personally am staying away from the Jets until further notice, but go ahead, knock yourself out.
So that's it for my look at CBI, specifically, the top ten. Perhaps I'll follow up on the bottom ten. Interestingly, the running back with the worst CBI in 2024 was Saquon Barkley. This is because he had a whopping 3.035 yards before contact and only 2.777 yards after contact. Why is this interesting? It further illustrates the point I made a few weeks ago when I was ranking players on new teams in 2024 and Saquon dominated. Even great running backs are going to struggle on bad offenses. Wanna guess who many yards before contact he had with the Giants in 2023? 1.4; under half as many than with the Eagles. Meanwhile, his yards after contact was 2.5 compared to 2.8 with the Eagles. So yeah, the team around you matters. Who knew?