The Wilk’s Formula is Too Wrong to Use

medal

I love powerlifting because of how objective it is.  We don’t have any of the debates one might find in gymnastics or figure skating or bodybuilding – sports in which the end result appears to be much more subjective to the observer.  In powerlifting you either lifted the weight to a certain standard or you did not.  And while every sport has its judging issues, for the most part with the respected federations those mishaps are few and far between.

All of that is well and good but when it comes time to pick the best lifter, now we have a problem.  The most commonly used formula is the Wilks.  It can be the deciding point if you can compete in a prestigious competition or not – for example you need a 430 Wilks formula to qualify for the Arnold.  And put simply, the Wilk’s formula is too wrong to use.

Let me use an example to highlight why this is the case.  I recently assisted a friend of mine in hosting an informal bench press competition at a military base.  He had weight classes but he wanted to give a “best bench” award.  These soldiers were not seasoned lifters and most were lifting 225 to 275 at normal body-weights, but there were benches that were clearly at the top of the field.

 

Those lifts were:

 

Lifter A: 175 lbs bodyweight and benched 330                    Wilks: 102

Lifter B: 285 lbs bodyweight and benched 405                     Wilks: 104 – Best Lifter

 

Wilk’s says that Lifter B is the best lifter.  I don’t know how you feel, but to me one of those lifts is clearly more impressive than the other, and it ain’t Lifter B.  The first lifter is benching close to double body-weight and he is benching 155 lbs over his body-weight.  The second lifter isn’t even hitting 1.5 x body-weight and he is benching only 120 lbs over his body-weight, and he is heavier.  Now I am not suggesting we use the old pound per body-weight rule where you take the total weight lifted and divide it by the body-weight, as everybody knows that is slanted toward lighter lifters.

The total pounds you are lifting over your body-weight should normally increase as your weight increases.  In both of these examples the lifters are lifting at least 1 lb per body-weight and that is a standard any high level powerlifter breaks in every lift.  Yet here one athlete was allowed to gain 110 pounds of body-weight and the lift only went up 75 lbs over his competitor’s bench.  Do you see the issue with that?

 

Lifter B: 285 lbs                  Lifter is lifting 1.42 lbs per bodyweight

Lifter A: 175 lbs                 Lifter is lifting 1.89 lbs per bodyweight

110 lb weight difference

Lifter B is 110 lbs heavier than lifter A, but he only lifts an additional 75 lbs of weight

75 / 110 = His extra weight is only adding .68 lbs lifted per bodyweight

 

As the lifters body-weight increases, he only has to increase his lift by .68 lbs per body-weight gained, which is a ratio that doesn’t match anything we see with lifters in real life (even the biggest, heaviest lifters – the best ones – are usually lifting close to 2 lbs per body-weight in the bench and well over 2 lbs per body-weight in the squat and deadlift.

For the formula to allow a lifter to gain 110 lbs of body-weight and with only 75 lbs of added strength and then it ranks that as more impressive, that is a big problem.  That is just not a little off, as though one discovers a team’s 3-point line is 2 inches closer to the basket than another teams.  This is like discovering that their 3-point line is 4 feet closer, it is immediate problem that needs to be fixed.  That kind of problem would ruin the game.  The good news is there is a solution.  That solution is to calculate a lifter’s AS.  That stands for allometric score, but AS is more user friendly and easier to say and from now on that is how I will refer to it.

My friend Greg Nuckols over at his excellent site Strengththeory.com addressed this issue as well.  He suggests, and I agree, that we should instead use allometric scaling to compare the lifts of one lifter to another.  This formula has a huge amount of theoretical evidence behind it in all sorts of applications and most importantly it simply works when you apply it powerlifting.  Here is the link to his full article, he explains the math in greater detail here.

You will still want to use a “best lifter” calculator as the formula is probably too complex to do in your head, luckily I have provided that for you here.  It is just as easy as it was before, you simply input the weight lifted and the bodyweight to find the best coefficient for that individual, and whomever has the higher coefficient wins.  When we calculate their AS and compare our lifters we get the following information:

 

Lifter A: 175 lbs body-weight and benched 330 lbs                              AS = 10.55

Lifter B: 285 lbs body-weight and benched 405 lbs                              AS = 9.40

 

Lifter A clearly has the more impressive lift.  I am not saying that Lifter A is stronger – strength typically refers to absolute strength and obviously Lifter B did indeed lift more weight than lifter A did.  But we have weight classes and we have formulas for a reason – people are interested in relative strength.  They want to compare one lift to another across body-weights, if this wasn’t important we would not have weight classes in the first place.

The current standard is way off. Wilks isn’t just a little bit off.  This isn’t a “well, it isn’t so bad let’s just keep the status quo” type of problem.  Wilks is fatally flawed and it should no longer be used to determine best lifter status.  Too much is at stake for it to be this wrong.  It is unfair for lifters to put forth all of that time, energy, and devotion to the sport only to be jilted come competition time.

It is time to get it right.  It is time to use Allometric Scaling to find a lifter’s AS and settle this once and for all.

Know someone who wants to get strong?...Share on FacebookTweet about this on TwitterShare on Google+Share on TumblrShare on RedditEmail this to someone

7 thoughts on “The Wilk’s Formula is Too Wrong to Use

  1. benchie

    In most credible bench press competitions, lifter A and lifter B would not be competing against each other for the same “best lifter” award. They would be split up in a lightweight/heavyweight set up where the divide would between around 200lbs bwt. There’s a lot of data out there that would support that the normal powerlifting wilks wasn’t made for bench only competitions, it becomes more accurate when dealing with 3-lift totals, but I think the problem here was oversight in set up.

    1. Tim Henriques

      Thanks for the post. There are some competitions that do separate out a heavy weight and a light weight best lifter but I would say that is a rarity and not the norm. A best lifter is usually just that – the best lifter at the meet. The point of this example was just to compare 2 lifts, Wilks doesn’t care if it is a squat, bench, deadlift, or total. The flaw in Wilks is once you get to a heavy bodyweight you only have to add a small fraction of strength for it to be considered a better lift.

      Here is another example.
      At a bodyweight of 220 if you lift 550 lbs that is a Wilks of 151.9

      At a bodyweight of 315 if you lift 605 lbs that is a Wilks of 152.9

      Both of these people are over 200 lbs and thus would be in the same category in your example. The 550 lb lift is obviously better but Wilks gives the nod to the 315 lb lifter. That lifter added 95 lbs of bodyweight and only 55 lbs of strength.

      If we use the AS the first lifter gets a score of 15, the second 13, the first lift is clearly better.

      It is not a lift dependent thing, it is just that once you hit about 275 Wilks is super skewed in favor of the heavyweight lifters.

      1. Carlos Matesanz

        While I might agree with wilks not being any good of a measure the problem in your reasoning is your statement:
        “The 550 lb lift is obviously better”

        Well, you find it better, or more impressive, and thus you find a formula that favors it to be more appropiate. Who decides which lift is better? It was for that reason that formulas were created. According to wilks lift B is better, according to AS lift A is better, according to “Matesanz’s magic formula” they might be tied.
        In that example you put out what happens if they both lift 10 more pounds?. How many pounds must guy B add to his total for every pound lifter A adds?

        No matter which formula you use, you’ll find examples someone might find unfair. That’s why noone should care about points.

        1. Tim Henriques

          I agree that no current formula is perfect, but I don’t agree we shouldn’t or can’t care about points or the idea of relative strength.

          I think it would be near universally agreed that a lifter 200 lb lifter benching 400 lbs is better than a 405 lb lifter benching 405 lbs.

          I also think it would be near universally agreed that a 150 lb lifter benching 300 lbs is worse than a 300 lb lifter benching 650 lbs.

          Both of those are discovered by “formula” so now the question becomes two fold for me. Which current formula is the best one we have available (I would argue the AS is) and what can we do to make it better?

  2. Pasquale

    I agree with you. Moreover, it doesn’t consider how tall you are. 200lbs at 1.60m and 200lbs at 1.95m are not the same. Obviously the second athlete has less musclar mass and strength.
    And we are still not considering arms and back length, which are smaller in the 1.60m athlete. So, I think it should be considered something more accurate.

  3. Miklos

    While the article makes a valid point, let me offer this:
    In conversation with Mr. Wilks he himself mentioned the Wilks formula is no good to calculate single lift results (bench only) as it’s way off. It was calculated and intended only for three lift competitions. Check three lift results and you’ll see the formula’s correctness vastly improves. Wilks said he never had the time to figure out a new table for single lift meets, so put the project on the back burner.

    1. Tim Henriques

      Thanks for the comment but I still don’t agree. For example if you have a 198 lb lifter that lifts 1700 lbs total and you compare a 275 lb lifter that lifts 2000 lbs total, the Wilks formula gives the nod to the heavier lifter by a significant margin (571 to 492). The 198 lb lifter is lifting 8.5 lbs per pound of bodyweight; the 275 lifter is lifting is lifting 7.27 lbs per bodyweight.

      The heavier lifter has added 77 lbs of bodyweight and only 300 lbs to their total (that isn’t even 4 lbs per pound of bodyweight). For them to have an equal score the 275 lifter only needs to beat the 198 lb lifter by 200 lbs in the total. I don’t think that is fair or accurate.

Leave a Reply

Your email address will not be published. Required fields are marked *