2015 IAAF World Championships Men's 100 Metres Sprint

Tomorrow, August 23, will be the date of the 100m semi-finals and finals of the 2015 IAAF World Championships. Most of this year's top sprinters qualified for the semis. Dasaolu and Bledman were eliminated in the heats. Others, such as Bailey-Cole, Richard Thompson, and Gemili missed out due to injuries. Some other sprinters including Ryan Bailey, Blake, and Carter were eliminated in their respective national championships. But despite some athletes missing, the start lists for the semi-finals and the finals will still be very good featuring stars like Gatlin, Bolt, Powell, Gay, Bromell, De Grasse, Vicaut, Rodgers, Ashmeade, Ogunode, Lemaitre, and Ujah, just to name a few. Bolt is facing his toughest competition yet and the 100m world record may be in jeopardy. It is even possible that for the first time in history, all eight sprinters will run sub-10 seconds (7 out of 8 sprinters were sub-10 in the finals of London 2012).

Here are the results that my model predicts:

Semi-Finals

Heat 1

1. Bromell (USA): 9.82s (9.56-10.08) Q
2. De Grasse (CAN): 9.95s (9.85-10.05) Q
3. Bolt (JAM): 9.96s (9.81-10.11)
4. Bruintjies (RSA): 9.97s (9.87-10.07)   
5. Su (CHN): 9.99s (9.89-10.09)       
6. Harvey (TUR): 10.03s (9.93-10.13)   
7. Reus (GER): 10.07s (9.97-10.17)
8. Lemaitre (FRA): 10.13s (9.94-10.32)

Heat 2

1. Gatlin (USA): 9.82s (9.64-10.00) Q
2. Ashmeade (JAM): 9.90s (9.63-10.17) Q   
3. Rodgers (USA): 9.92s (9.79-10.05) q
4. Ogunode (QAT): 9.92s (9.76-10.08)
5. Ujah (GBR): 9.94s (9.68-10.20)
6. Simbine (RSA): 9.97s (9.71-10.23)
7. Cadogan (BAR): 10.06s (9.96-10.16)       
8. Brown (CAN): 10.08s (9.98-10.18)

Heat 3

1. Powell (JAM): 9.91s (9.80-10.02) Q   
2. Gay (USA): 9.91s (9.72-10.10) Q
3. Vicaut (FRA): 9.91s (9.68-10.14) q
4. Gittens (BAR): 10.02s (9.92-10.12)
5. Meite (CIV): 10.05s (9.95-10.15)
6. Kilty (GBR): 10.05s (9.95-10.15)
7. Taftina (IRI): 10.10s (10.00-10.20)
8. Martina (NED): 10.18s (9.88-10.48)

Final

1. Gatlin (USA): 9.82s (9.64-10.00)
2. Bromell (USA): 9.82s (9.56-10.08)
3. Ashmeade (JAM): 9.90s (9.63-10.17)
4. Powell (JAM): 9.91s (9.80-10.02)
5. Gay (USA): 9.91s (9.72-10.10)
6. Vicaut (FRA): 9.91s (9.68-10.14)
7. Rodgers (USA): 9.92s (9.79-10.05
8. De Grasse (CAN): 9.95s (9.85-10.05)

Gold: Gatlin (USA)
Silver: Bromell (USA)
Bronze: Ashmeade (JAM)

World Champion: Justin Gatlin (USA)

This quadratic regression model shows that Gatlin would win it all. Here is what some other models say:

Moving average (2 period): 1) Gatlin, 2) Powell, 3) Gay

Linear: 1) Gay 2) Gatlin 3) Vicaut

Exponential: 1) Gay 2) Gatlin 3) Vicaut

However, despite these models, I still predict that Usain Bolt will win. Here's why.

 

Bolt 2008 pre-Olympics: 9.72s

Bolt 2008 Olympics: 9.69s

Difference: 0.03s

Bolt 2009 pre-World Championships: 9.79s

Bolt 2009 World Championships: 9.58s

Difference: 0.21s

Bolt 2012 pre-Olympics: 9.76s

Bolt 2012 Olympics: 9.63s

Difference: 0.13s

Bolt 2013 pre-World Championships: 9.85s

Bolt 2013 World Championships: 9.77s

Difference: 0.08s

Average Difference: 0.1125s

Now applying this difference,

Bolt 2015 pre-World Championships: 9.87s

Bolt 2015 World Championships: 9.76s (9.66-9.84)

Meanwhile for Gatlin,

Gatlin 2012 pre-Olympics: 9.80s

Gatlin 2012 Olympics: 9.79s

Difference: 0.01s

Gatlin 2013 pre-World Championships: 9.85s

Gatlin 2013 World Championships: 9.89s

Difference: 0.04s

Average Difference: 0.025s

Now applying this difference,

Gatlin 2015 pre-World Championships: 9.74

Gatlin 2015 World Championships: 9.72s (9.70-9.73)

Note that 2010 and 2014 were gap years (no major competitions other than Diamond League Meets) and Bolt false started and was disqualified in 2011, while Gatlin was still on the road to recovery following his drug bans. Hence, these years have been omitted. 

This shows that it will be very hard for Gatlin to run sub 9.7, but for Bolt it is possible. Gatlin has been very consistent, constantly running times in the 9.70's, but he has so far failed to run in the 9.6's. Meanwhile, for the defending champion, this is still possible. 

Another important factor to consider are basic times: times adjusted for wind speeds and elevation. Gatlin's best basic time of 2015 is 9.78s while for Bolt it is 9.80: a difference of only 0.02 seconds.

Other challengers include Bromell, the 20 year-old sprinting sensation. However, he is still inexperienced and young. Gay and Powell can clock speedy times, but often under perform in major competitions. If Bolt were still injured, I'd predict that Gatlin would win. But now I'm saying Bolt first, then Gatlin, and Powell with the bronze. But either way, this race will be a good one.