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Gay (left) aiming to break the record of 1968 Olympic champion Smith (right)
By Mark Butler
BBC Sport's athletics statistician
Remember how shocked we were by the way Michael Johnson and then Usain Bolt took such huge chunks from the world 200m record?
Well 44 years ago, an American athlete was responsible for an even bigger margin of improvement. On 7 May 1966 in San Jose, 21-year-old Tommie C. Smith covered the distance in 19.5 seconds to take half a second from the previous record.
On Sunday, at the Great City Games in Manchester, Smith will be in attendance to see Tyson Gay and others try to beat his mark on a specially-constructed track at Deansgate.
Two years after breaking that record, Smith would become the Olympic 200m champion amid well-documented controversy, but it could be argued that his 19.5, set on a cinder track, was an even greater performance.
Why I gave the 'Black Power Salute' - Tommie Smith
After 44 years "Tommie Jet" is still the world record holder, even though Johnson (19.32) and Bolt (19.19) have faster times. The reason is, of course, that Smith's 19.5 was set on a straight track.
In the 1960s, the straight 200 metres was a separate world record event for men. The sport's governing body (IAAF) has since deleted this variation from its list of official records, but no one else has run faster than Smith on a 200m straight.
On the Deansgate track last year, Bolt ran the fastest ever 150m.
When Smith ran his 19.5, it was rated as the greatest-ever performance in track and field, according to scoring tables in use at the time. It was also a double world record because there were timekeepers at both 200m and 220 yards. His time at the longer distance was also 19.5.
So how could someone clock the same time at two different distances ? Only hand timing was in use. At 200m the three timekeepers stopped their watches at 19.4, 19.5 and 19.6. At 220 yards another trio recorded times of 19.5, 19.5 and 19.6.
The rules in force at the time stated that if two or more times agreed then that time should be taken as official, but if all were different then the middle should be taken.
Following that principle, 19.5 was accepted in both cases and the 220 yard mark will definitely still stand after Manchester because Gay and Co will only be racing up to 200m.
Bolt storms to victory over 150m in Manchester last year
Smith was unquestionably the finest all-round sprinter of his time. In 1966 he set world records around a bend over 200m/220y, missed the world 100m record by 0.1 sec and ran a 400m relay leg in 43.8, when no man had run faster than 44.9 from blocks. He was also a world-class long jumper.
Smith set further world records at 400m/440y in 1967 and went on to win the 1968 Olympic 200m in Mexico City with the first ever legitimate electrically-timed sub-20.
It's obvious that a sprinter can run faster down a straight than around a bend.
Bolt proved that last year when he clocked 14.35 for 150m in Manchester in May, then was timed at "only" 14.44 to that point during his epic 200m in Berlin, having run the first 100m on a curve.
When straight "furlongs" were run frequently, it was felt that we could add 0.465 to straight times to find the equivalent mark on a bend. A time of 19.50 straight would therefore be worth 19.965 on the bend.
Gay's best 200m on a bend is 19.58. If we subtract 0.465 from that we get a number less than 19.19.
So if conditions are good, there is just the possibility that Bolt's Berlin time could be bettered in Manchester.
It wouldn't be an official world record, but it would be the fastest 200m ever run, which would be quite a sight to see on the A56.
Progressive world records at men's 200m straight:
21.2 secs Bernard Wefers (USA) in New York, 30 May 1896
21.2 Ralph Craig (USA) in Philadelphia, 28 May 1910
21.2 Donald Lippincott (USA) in Cambridge, Mass, 31 May 1913
21.2 Howard Drew (USA) in Claremont, 28 Feb 1914
21.2 George Parker (USA) in Fresno, 2 Oct 1914
20.8 Charlie Paddock (USA) in Berkeley, 26 March 1921
20.8 Charlie Paddock (USA) in West Orange, 6 Sept 1924
20.6 Roland Locke (USA) in Lincoln, 1 May 1926
20.6 Ralph Metcalfe (USA) in Budapest, 12 Aug 1933
20.3 Jesse Owens (USA) in Ann Arbor, 25 May 1935
20.2 Mel Patton (USA) in Los Angeles, 7 May 1949
20.1 David Sime (USA) in Durham, NC, 11 May 1956
20.0 David Sime (USA) in Sanger, 9 June 1956
20.0 Frank Budd (USA) in Villanova, 12 May 1962
20.0 Tommie Smith (USA) in San Jose, 13 March 1965
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