The best formulas to use are the Siff formulas. For Weightlifting, the formula is:
Total=a-b*B^(-c), where B is bodymass in kg, a = 512.245, b = 146230 and c = 1.605.
For Powerlifting, the same equation applies, but the constants are: a=1270.4, b=172970, c=1.3925.
For women's weightlifting:
Total=c-a*exp(-b*B), where B is bodymass in kg, a=943.063, b=0.05142 and c=257.314.
To compare the performances of lifters of different bodymass, simply substitute each lifter's bodymass in the relevant equations above to calculate the Total (or lift) expected for a top world class lifter. Then divide each lifter's actual Total by this value and multiply by 100 to obtain the percentage of the world class lift achieved by each lifter.
The 1996 formula is: 10^(a(x^2)), where a=1.348196177 (men), =1.016281142 (women), and x=log(w/135.39) (men) =log(w/110.69) (women), where w=bodyweight. The formula is used for athletes less than or equal to 135.39kg (men) 110.69kg (women) bodyweight. For athletes greater than this bodyweight, the coefficient is 1.
Powerlifting has similar formulas: the Schwartz formula was the original; later, the Malone formula was formulated for women. Currently, the Wilks formula is most commonly used for both men and women.
The Malone-Meltzer coefficients are used to compare totals of masters lifters of different ages. Track and field has similar age-grading formulas for each event.
The Siff and Malone-Meltzer formulas are given in formulas.xls, a Microsoft Excel file. I have also superimposed Siff isocurves onto my chart of absolute records.
So to determine who is the most efficient lifter, or who lifts the most pound-for-pound, one would find the tangency of a ray from the origin to the Siff isocurves. This occurs at a bodyweight of about 62kg for men and 50kg for women. This defines the most efficient bodyweight, given the current pool of lifters. Heavier athletes lift more, but an additional kilogram of bodyweight generally returns less than additional kilogram to the total.
Of course, this does not mean that the most efficient bodyweight for all individual men is 61kg. That depends upon the individual's characteristics--most notably frame. When one is lower than their ideal bodyweight, their bone mass is a greater percentage of their muscle mass, and the bone-muscle system is less efficient. In general, the most efficient weight class (men and women) is the second heaviest.
Sinclair formula: My major criticism of the Sinclair formula is that the coefficients are the same for athletes above 135.39 kg of bodyweight. Therefore, two athletes that total 400 kg, one weighing 135.4 and one weighting 170, would score identical. I believe the better lifter in this case is the more efficient lifter: the lighter one.
So a tiebreaker rule might be that the lighter lifter is ranked ahead of the heavier lifter. But this is exactly what the Sinclair formula is supposed to do. The Siff formulas are upward-sloping for all bodyweights. Furthermore, the Siff formulas are not piecewise.
Malone-Meltzer coefficients: The current table of coefficients are not generated by a formula. Therefore, a plot of the coefficients and isocurves produces a wavy line with many inflection points.
Solution: reduce the number of inflection points to one to produce a smooth S-curve. My proposed values are given in the Excel chart. In addition, to extend the chart, the coefficients should increase by 0.02 for every year above the age of 90.
Also, when the next Malone-Meltzer update is done, I suggest separate tables for men and women. Men and women may have different rates of physical decline at various age ranges.
The following describes the procedure for conducting a formula competition (as opposed to a standard weight class competition): This is useful in small meets, where there would be only one or two entrants in some weight classes.
First, athletes weigh in one time between two and one hours before the competition. (There are no extra weigh-ins to make a certain weight class.) After last weigh in, all lifter's weights are revealed. Then athletes declare their opening attempts. (Throughout the competition, athletes may adjust declared attempts upward.) Competition ascends by formula applied to the snatch; bar weight must be increments of 2.5kg. In the jerk, competition ascends by formula applied to the jerk (or alternatively applied to the total). Bar weight must be increments of 2.5kg.
Example: four lifters weigh in at:
bwt opening att Siff value A 60.00 70 .227604 B 67.69 82.5 .240124 C 84.40 97.5 .247543 D 94.00 95 .230210The starting order is A-D-B-C. However, if lifter A takes second attempt at 75, this is worth .243861, so lifter A will take second attempt before lifter C takes first attempt.
If lifter A makes 75 on second attempt, Lifter D will then have to lift 102.5 to surpass lifter A.
Also, the Siff value and the Malone-Meltzer coefficients can be multiplied to make an age-handicap, bodyweight-handicap combination competition.
Meltzer, David E. (1994) "Age dependence of Olympic weightlifting ability" Medicine & Science in Sports & Exercise 1053-67.
Meltzer, David E. (1996) "Body-mass dependence of age-related deterioration in human muscular fuinction" American Physiological Society 0161-7567, 1149-55.
Siff, Mel C. & Verkhoshansky "Supertraining" 1998, Ch 3.3.
The Evolution of Bodymass Adjustment by Mel Siff
More on the Wilks Formula by Sean Anderson
http://www.geocities.com/aedziepak/strength/formulas.htm