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born2fly
February 27th, 2003, 11:27 AM
I've been trying to find site that shows conversion from long course meters into short course yards. Can anyone point me in right direction or let me know say per 50 what the time difference is?

Thanks in Advance,
greg

Bert Petersen
February 27th, 2003, 11:50 AM
Multiply by 9, after converting to seconds, then move the decimal.
It is not a straight line conversion, meters to yards, as that is not accurate due to the extra length of the pool. This works for me.
Examples : 50m fly @ 30.71; 30.71 x 9 = 27639 = 27.64
100m br @ 1:19.84 or 79.84 x 9 = 71856 = 1:11.86
The factor for long course is .875
If you wish, just subtract 10 % and you will be close enough.

Bert

valhallan
February 27th, 2003, 12:01 PM
Greg,

This link is used by one of our local meet sponsors to assist with entry times. (Their pool has a bulkhead between the swimming and diving areas. And it gets shifted back and forth a few times throughout the year.)

(http://www.swiminfo.com/results/conversions.asp)

Jim VB
March 9th, 2003, 10:05 AM
There are a number of different conversion programs, which I am sure you have found out by now. They tend to have minor variations in them. They will only be close because each swimmer is different in how he or she responds to the differences. I played around with a spreadsheet trying to match some conversion programs, and was able to do it to within hundredths of a second for all distances and times. even counting "rediculous" times just to test the spreadsheet. What it took to do included the following:
Meters to yards distance conversion (the easy part).
Assign a time advantage per extra turn, often 1.00 sec. or very close. for example, the 200 meter long course has 3 turns, and the 200 yard short course has seven, and in one program I found, if you put it that you can do the 200 meter in 4 (!!) sec. it will say that you can to the 200 yd short course in 0.00 exactly. So it appears to be assigning 1 sec per extra turn in the swim.
Another factor needed to match all distances to the hundredths, was apply kind of a "y intercept" of 1 second for the start, regardless of the length of the swim.
One program liked me to represent the "extra water" in the long course meter pool because the 25 yard minus push-off and glide is much less than .45 of a 50 meter minus push off and glide, so one attempt at matching predictions worked well with some other number like 1.14 instead of 1.1 for the extra distance. It seems that almost any swimmer will attest to the big difference between long/meters and short/yards and I think that this "extra water " is a big part of that.
When rambling on the Emmet Hines about this, he e-mailed back that the turns affect each swimmer differently because some are better than others, and swimmers tolerate the oxygen debt of the long glide differently. So I think that any conversion will get you close, but beyond that , the swimmers will respond as an individual. One of my sons pointed out that a 25 yard length of fly can be 7-8 strokes, but one length of 50 meter fly can be more that 25 strokes, whereas a straight 10% meter/yard would predict no more than 18. All that water in the 50 meter rewards better swimming technique.