Prediction Time – What Will It Take To Make The DI Championships?

by SwimSwam Contributors 17

February 09th, 2017 College, News

Jacob Skipper is the swimming SID at William & Mary.  He stays away from the water.

Now that conference season is upon us, one of the questions that preys upon everyone’s mind is what will it take to get in?  Below are my semi-educated guesses, along with the rationale I used to arrive at them.  This is a tool I’ve come up for my own use the last couple years, so that I can try and have a heads-up when an athlete is nearing NCAA qualification.

The Method

I took the last several years of final-invited times off the NCAA psych sheets, dating back to 2011, and calculate the year-by-year change.  Then, I use a simple formula to average all of those changes, with an extra weight to both the most recent year-change, and the year-change to the equivalent earlier year, and add that to last year’s invited time. So, for 2017, I weight the change between 2015 and 2016, as well as the change between 2012 and 2013 (the most recent year after an Olympics year).  The excel formula is average((2*mostrecent),(2*mostsimilar), N1, N2, N3, etc…), where the Ns are the other years changes (in this case, 11 to 12, 13 to 14, and 14 to 15).  The double-weight to the most recent year is a change for this season.  Also new to this year is a weight to try and correct for the error I found from last year’s predictions.  In the example:  I had projected last year’s men’s 500 free to need 4:17.01 to qualify, and the last invited was 4:17.73.  Dividing the actual by the projected gives an error of 1.002817055.  This year, once I had done the original calculation, I then multiplied it by the error factor to achieve the refined projection.

Assumptions

– Only looking at the individual swimming events.  The relays are now entirely dependent on the individual qualifications, so it’s not useful to figure out the time you need to go – it’s conceivable that a school could set the world record in (say) the 200 medley relay, but not swim at NCAAs because no one qualified individually.

– Similarly, didn’t look at the diving events.  Once you meet the regional standard, it’s entirely dependent on the competition at the zone meets.

– I only looked at the official psych sheets cut line for each year.  If there was a late-add alternate, they don’t figure in.

Disclaimer

I am in no way affiliated with the selection committee, nor am I psychic (that I’m aware of).  These are predictions and guesses, informed only by my knowledge of numbers and 10-year experience as a collegiate SID.  If you rely on these numbers, and you or your swimmer misses out on the NCAA Championships because you thought you/they were safely in and the cutoff came in lower, that’s your own mistake.

The Numbers

With no further ado, here is the table of projections.

Men’s Time Event Women’s Time
4:18.31 500 Free 4:42.37
1:44.24 200 IM 1:57.67
19.54 50 Free 22.30
3:45.88 400 IM 4:09.79
46.30 100 Fly 52.75
1:34.80 200 Free 1:45.73
52.87 100 Breast 1:00.58
46.56 100 Back 52.89
15:01.02 1650 Free 16:17.92
1:41.80 200 Back 1:54.28
43.16 100 Free 48.65
1:55.58 200 Breast 2:10.55
1:43.56 200 Fly 1:57.07

Here is a simplified source table – the columns are what I projected for last year, what it actually took, what the absolute (in seconds) and percentage error (absolute error divided by the actual invite).  Negative numbers in the error denote that I projected a slower time than it actually took to make the meet.

Event 2016 Projected 2016 Actual Absolute Error Pct. Error
Men’s 500 Free 4:17.01 4:17.73 0.72 0.28%
Men’s 200 IM 1:44.37 1:44.41 0.04 0.04%
Men’s 50 Free 19.50 19.53 0.03 0.15%
Men’s 400 IM 3:44.85 3:45.61 0.76 0.34%
Men’s 100 Fly 46.49 46.44 -0.05 -0.11%
Men’s 200 Free 1:34.43 1:34.67 0.24 0.26%
Men’s 100 Breast 52.88 52.92 0.04 0.07%
Men’s 100 Back 46.35 46.51 0.16 0.34%
Men’s 1650 Free 14:58.24 15:00.11 1.87 0.21%
Men’s 200 Back 1:41.65 1:41.92 0.27 0.26%
Men’s 100 Free 42.93 43.05 0.12 0.28%
Men’s 200 Breast 1:54.92 1:55.31 0.39 0.34%
Men’s 200 Fly 1:43.49 1:43.65 0.16 0.16%
Men’s Error Average 0.20%
Women’s 500 Free 4:43.08 4:42.69 -0.39 -0.14%
Women’s 200 IM 1:57.90 1:57.90 0.00 0.00%
Women’s 50 Free 22.35 22.35 0.00 -0.02%
Women’s 400 IM 4:12.01 4:11.05 -0.96 -0.38%
Women’s 100 Fly 52.74 52.77 0.03 0.06%
Women’s 200 Free 1:45.80 1:45.84 0.04 0.04%
Women’s 100 Breast 1:00.70 1:00.66 -0.04 -0.07%
Women’s 100 Back 52.96 52.93 -0.03 -0.05%
Women’s 1650 Free 16:17.70 16:17.64 -0.06 -0.01%
Women’s 200 Back 1:54.32 1:54.47 0.15 0.13%
Women’s 100 Free 48.84 48.77 -0.07 -0.14%
Women’s 200 Breast 2:11.11 2:10.89 -0.22 -0.17%
Women’s 200 Fly 1:56.93 1:57.02 0.09 0.08%
Women’s Error Average -0.05%

 

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Votehillary
7 years ago

Amazingly, the 2 and 5 free q times will be faster than you state. 418 won’t make it

Swammer
Reply to  Votehillary
7 years ago

FYI. I 4:18 last year. Did not make it

buckeye499
7 years ago

I think some of the events might be a little faster this year because some of the top talent wasn’t in school last year. They were preparing for trials. Also, some of those in school might have been looking forward to and possibly even practicing long course in anticipation of trials. Those swimmers would be more focused on short course this year. It will be interesting to see how close the predictions are.

Jacob Skipper
Reply to  buckeye499
7 years ago

In reply to both you and swammer, I agree, it’ll be interesting to see how it all turns out. The question of Olympic redshirts is indeed intriguing – I tried to control for it by giving the weight to the similar year from the previous Olympic cycle (just like last year, where it was going the other way and trying to predict the slow down caused by people not swimming NCAAs). Like I said, it’ll be interesting to see whether or not it was an effective control at all. One question would be what the ratio of returning redshirts and notable newcomers (i.e., Ledecky and crew) is to the graduated and others who aren’t in the mix this year. Would… Read more »

Swammer
7 years ago

It’s quite an analysis but these times seem a little slow. I don’t have any sort of analysis behind what I’m claiming but I have a strong inclination it’s gonna take faster times to make it this year.

ct swim fan
7 years ago

I see some dope has once again just for the hell of it, gone through here and down voted pretty much every comment . Pathetic!

Lane 11
7 years ago

Excellent analysis! Have been reading Jacob Skipper’s work as the media relations guy for William & Mary swimming for the past few years. One of the beat Sports Information guys in college athletics. He does great work promoting Tribe Swimming.

Dawgpaddle
7 years ago

Is it true that if a school posts an A relay standard, those athletes can compete in that and any other relay?

Dawgpaddle
Reply to  Dawgpaddle
7 years ago

So the only way a swimmer can get to the meet is by qualifying individually? Relays are not invited? Please clarify. Thanks!

Coach Hannah
Reply to  Dawgpaddle
7 years ago

Relay only swimmers are selected by the coach, and they would attend the meet to swim in only the relays the team needs them in.
To swim individually, you must qualify individually.
To swim on a relay, you must be an individual qualifier OR one of the four relay only swimmers the team takes to the meet.

Jacob Skipper
Reply to  Dawgpaddle
7 years ago

If a school gets 1-3 swimmers invited, then they can swim any relay that they have “A” cut for. If they have 4+ swimmers invited, then they can swim any relay that they have “B” cut for. That’s the only way you get to swim relays now. If the team wants to, they can bring up to four swimmers who will only swim the relays (on the school’s dime, vs. the NCAA who pays for all the actual invited people). Those relay-swimmers CANNOT swim any individual events.

Dawgpaddle
Reply to  Jacob Skipper
7 years ago

Thank you

dmswim
7 years ago

This is awesome! Thanks!

Louisiana Swimmer
7 years ago

What is a swimming SID?

completelyconquered
Reply to  Louisiana Swimmer
7 years ago

It’s the Sports Information Director. They are the people that will collect media and put together media for athletics at universities.

barbotus
Reply to  Louisiana Swimmer
7 years ago

Sports Information Director

coacherik
Reply to  Louisiana Swimmer
7 years ago

Sports Information Director.. Based on this report, one who actually takes the time to get to know the sport he is responsible for. Thank you!