The document discusses the annual Iditarod sled dog race from Anchorage to Nome, Alaska. It notes that winning times have steadily decreased over the years, now hovering around 200 hours. Tables of winning times from 1973 to present are analyzed to calculate average speeds, which have increased from around 2 mph to over 5 mph as mushers have improved techniques and care for their dog teams.

1. The Iditarod Race
Math in the News
Issue 95

2. The Iditarod Race
This year’s Iditarod happens during a particularly harsh
winter. This 1000-mile race is an endurance
competition for musher and dog alike. In this issue we
measure the average speed of the racers.

3. The Iditarod Race
The Iditarod Race began in 1973, in part to
commemorate a heroic Anchorage-to-Nome delivery of
diphtheria serum that made a husky by the name of
Balto famous to children the world over. It is now a
world-wide sporting event.

4. The Iditarod Race
This is the map of this year’s Iditarod Race. This is the
Northern route. On odd-numbered years there is a
Southern route. As you can see this 975-mile route is
not a straight-line distance from Anchorage to Nome.

5. The Iditarod Race
This table shows the
winning times for the all
the racers since the first
Iditarod. The first thing to
notice is that these times
have steadily increased,
as mushers have
improved their speeds
over time. (Table
continued on the next
slide.)
Source: Iditarod.com
Year
Days
Hours
Minutes Seconds
1973
20
0
49
41
1974
20
15
1
7
1975
14
14
43
15
1976
18
22
58
17
1977
16
16
27
13
1978
14
18
52
24
1979
15
10
37
47
1980
14
7
11
51
1981
12
8
45
2
1982
16
4
40
10
1983
12
14
10
44
1984
12
15
7
33
1985
18
0
20
17
1986
11
15
6
0
1987
11
2
5
13
1988
11
11
41
40
1989
11
5
24
34
1990
11
1
53
23
1991
12
16
34
39

6. The Iditarod Race
Year
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Days
10
10
10
9
9
9
9
9
9
9
8
9
9
9
9
9
9
9
9
9
9
Hours
19
15
13
2
5
8
5
14
0
19
22
15
12
18
11
5
11
21
23
18
4
Minutes
17
38
2
42
43
30
52
31
58
55
46
47
20
39
11
8
46
38
59
46
29
Seconds
15
15
39
19
0
45
26
7
6
50
2
36
22
31
36
41
48
46
9
39
26

7. The Iditarod Race
Take the data in the table and input it into a
spreadsheet. Create a new column to convert the
times to hours.
Year
1973
1974
1975
1976
1977
1978
1979
1980
Days
20
20
14
18
16
14
15
14
Hours
0
15
14
22
16
18
10
7
Minutes Seconds Hours
49
41
480.83
1
7
495.02
43
15
350.72
58
17
454.97
27
13
400.45
52
24
354.87
37
47
370.63
11
51
343.20
=B2*24+C2+D2/60
+E2/3600

8. The Iditarod Race
Create a line graph of the data for the winning times.
Here you can see how the winning times have steadily
decreased, and now hover around 200 hours.

9. The Iditarod Race
Now add another column to the spreadsheet to
calculate the average speed.
Year
1973
1974
1975
1976
1977
1978
1979
1980
Hours
480.83
495.02
350.72
454.97
400.45
354.87
370.63
343.20
Average
Speed (mi/h)
2.028
1.970
2.780
2.143
2.435
2.747
2.631
2.841
=975/F2

10. The Iditarod Race
Here is a line graph of the speed data, and it clearly
shows a steady improvement in the average speed.

11. The Iditarod Race
Why have the times
increased so steadily?

12. The Iditarod Race
First, let’s refine our speed estimate. The average
speed we calculated assumes the mushers are riding
24/7, which isn’t true. There’s a mandatory 40-hours of
rest minimum. Adjust your spreadsheet to see the
impact on the speeds.
Year
1973
1974
1975
1976
1977
1978
1979
1980
Hours
480.83
495.02
350.72
454.97
400.45
354.87
370.63
343.20
Average
Speed (mi/h)
2.028
1.970
2.780
2.143
2.435
2.747
2.631
2.841
Reduce by 40

13. The Iditarod Race
Here is a double line graph of the speed data sets, and
it clearly shows an increase in the average speed.

14. The Iditarod Race
Now assume that of the remaining hours, a musher
spends between 15% to 20% of their time resting.
(People normally spend 33 1/3% resting.) How does
this affect the speed? Here is a multi-line graph
showing such an adjustment.

15. The Iditarod Race
• Continue investigating ways in which racers have
increased their average speed. Keep these
questions in mind:
•
•
•
Do racers maintain the same speed throughout the entire
race? If not, how does their speed vary?
How does the number of dogs used in the race affect the
average speed?
What techniques do racers use to improve their speed?