Performance
Quotients:
A Performance Measurement
Tool for MTF Awards Committee
Dave Clingan 1/12/08
DEFINITION OF PQ
Performance Quotient (PQ)
is a formula for measuring the strength of a track or field mark as compared
with the American Record and the top three ranked marks in the same event and
age group. As an indicator of
performance strength, it is designed to be used as a tool to assist the MTF
Awards Committee in evaluating and comparing the accomplishments of athletes in
various events and age groups.
There is no measuring
tool or system that can definitively determine the better of two marks in
different competition events.
However, the PQ can provide some insight as to which athlete was more
dominant within his/her age group and event during the year.
The MTF rankings database
provides the source of marks used in PQ calculation.
CALCULATION OF PQ
The formula for PQ is as follows:
P = Performance
R = American Record
A = Top Ranked Mark in
the event
B = Second Ranked Mark in the event
C = Third Ranked Mark in
the event
V = Average of R, A, & B
For Distances (field
events), PQ =
97 x [P – (A
– C)x.1]
---------------------------
V
For Times (running
events), PQ =
97 x V
--------------------------
P – (C
– A)x.1
CORRECTIVE MECHANISMS
(1) The formula contains
a correction for events in which the American Record is "Bemanesque",
meaning so superior that any seasonal mark measured against it will always
be disadvantaged. Therefore,
the American Record is averaged with the top two seasonal marks (V = average
of R, A and B), to adjust for hyper-superlative records.
(2) The formula contains a correction for a bias that has been referred to as
the "compression effect". It is
the nature of some events that marks are clustered very closely together, while
others are more spread out. In
compressed events, the top ranked mark typically has greater mathematical
proximity to the record. For example, the top ranked M40 100m time of 10.50 is
93% of the WR (9.79); whereas the top ranked M40 discus throw of 52.53m is only
71% of the WR (74.08). Common
sense tells us that the difference is due more to the compression effect than
to a significant quality discrepancy between the time and the throw.
In the PQ formula, the compression correction is expressed as (A – C) x.1 for distances and (C
– A) x.1 for times. This
expression provides for an adjustment that reflects range of separation between
the first ranked mark and the third ranked mark in the event. The greater the range, the greater the
correction.
(3) Events in which there
were only one or two athletes were not amenable to the PQ formula. This occurred primarily in older age
divisions (85 and up). In order to
include outstanding performances in such cases, a simplified version of the
formula was used:
V = average of the American Record (R) and the Performance (P)
For Distances: PQ = 100 x
P/ V
For Times: PQ = 100 x V/P
VALIDATION
PQ scores were calculated
for performances derived from the 2007 outdoor rankings database. This database consists of over 5,400 masters
athletes. Not included for purposes of this study are: (a) indoor marks, this
study are 30-34, (b) athletes age 30-34, and (c) combined events scores) Athletes
who's PQ scores placed them in the top 40 within their respective age bracket
(M35-59, M60+, W35-59, W60+) were extracted from the data base and closely
examined. Extraction of the top 40 athletes in each bracket is accomplished
by selecting only those athletes who scored above a certain PQ threshold (approximately
96). This data is contained here.
MICRO VALIDATION
Micro validation is a
process of looking at the selected PQ scores and assessing whether the data
makes sense. 13 the top 17 M35-59
PQ scores exceeded previous American Records, which is to be expected. The highest score, achieved by M35 Weight
Thrower Aaron Linerud at 106.83 was remarkable in that it not only broke the AR
by a substantial margin (topping the old mark of 12.15m by almost 4m) but also
in that it surpassed the second and third ranked marks by margins of about one
and two meters respectively. Not
all top PQ scores involve record-breaking performances. For example, Peter Magill did not break
his own American Record in the M45 3000m, but he achieved the 9th
highest PQ at 100.34 with a time of 8:48.80 due to its superiority over the
second and third fastest times, which were nearly one minute slower.
It is expected that an
athlete who is consistently good at several events would achieve similar PQ
scores in each of those events.
Here is an example:
NOLAN SHAHEED M55
800m 2:05.43 = 99.38
1500m 4:22.89 = 98.59
5000m 16:40.14 = 98.53
MILE 4:42.7 = 98.24
In my experience with these
particular running events, I believe the Shaheed's times are very comparable
and therefore the similarity in PQ scores is consistent with my expectations.
Obtaining more micro validation feedback from other athletes with experience in
other competition categories would be extremely beneficial. For example, I would like to hear from
throwers, jumpers and sprinters if the PQ scores in those events are consistent
with their expectations based on their experience.
MACRO VALIDATION
Macro validation involves statistically analyzing the PQ scores in various categories
to look for undesired trends or biases in the system. The PQ formula should not inherently favor one event
over another, or one age group over another. In other words, all athletes should have an equal shot at
achieving an elite level PQ score regardless of which event they compete in or
which age group they are in. The charts below show how many athletes achieved
PQ scores ranked in the top 40 highest scores, based within various types of
events and within different age groups.
Additional study would be helpful in interpreting this data, but the
chart does not reveal any glaring biases or inequities which would not likely
be explained by variances in the number of active athletes per event or age
group and other factors. Athletes of all events and all age groups are well
represented.
Distribution of TOP 40 PQ Scores Among Events
|
|
Distance |
Sprints |
Throws |
Jumps |
Hurdles |
|
M35-59 |
10 |
12 |
9 |
6 |
3 |
|
M60+ |
8 |
10 |
10 |
8 |
5 |
|
W35-59 |
19 |
9 |
5 |
5 |
6 |
|
W60+ |
11 |
13 |
15 |
6 |
4 |
Distribution of TOP 40
PQ Scores Among 5 Year Age Groups
|
M35-59 |
W35-59 |
|
M60+ |
W60+ |
|
M35 = 4 |
W35 = 5 |
|
M60 = 6 |
W60 = 8 |
|
M40 = 9 |
W40 = 12 |
|
M65 = 8 |
W65 = 7 |
|
M45 = 12 |
W45 = 13 |
|
M70 = 5 |
W70 = 8 |
|
M50 = 10 |
W50 = 5 |
|
M75 = 4 |
W75 = 6 |
|
M55 = 8 |
W55 = 8 |
|
M80 = 6 |
W80 = 6 |
|
|
|
|
M85 = 4 |
W85 = 3 |
|
|
|
|
M90 = 3 |
W90 = 3 |
|
|
|
|
M95 = 4 |
|
RECOMMENDATIONS
I recommend that PQ scores be calculated by the Masters T&F rankings system
for the 2007 Indoor and Outdoor seasons.
It will be possible to produce a summary page of top PQ performances for
the entire 2007 year as a tool for helping to identify the most exceptional
marks of that year.
PQ scores can be used by the awards committee for the purpose of evaluating
performances as they see fit. However, it is not recommended that PQ scores be used as the
sole criteria in evaluating the relative merit of different performances. It is only intended as a tool to assist
in making such an evaluations.
Finally, use of PQ scores in the process of evaluating 2007 awards nominees
will undoubtably produce valuable feedback which will help improve the system.