The AMA Supercross Championships head to Phoenix’s Chase Field for round two this coming Saturday, an ideal time to look over some of the interesting statistics concerning this United States (and FIM-sanctioned World Championship) series …

►This year is the 40th anniversary of the AMA US Supercross Championships

►The first points-paying race was held on March 8, 1974 and Pierre Karsmakers won on a Yamaha

►Later that year, Karsmakers went on to win the first ever United States Supercross Championship

►Since 1974, there have been 573 races of the US Supercross Championships

►After Ken Roczen’s win last weekend, there have now been 57 different winners of an AMA Supercross main event

►There have been 20 different winners of the US Supercross Championship

►There have been 7 different brands to win a US Supercross main event

►Anaheim holds the record for most supercross races held and last weekend become the first venue to host 62

►Since 1974, Anaheim has hosted a US Supercross Championship race every year with the exception of ’74, ’75 ’80, ’88, ’97, and ’98

►In 17 of 40 seasons, the winner of race one would go on to win the championship

►In 32 of 40 seasons, the champion appeared on the podium for the first race

►Ryan Dungey gave KTM their first-ever win at Angel Stadium at the third race in Anaheim last year … now Roczen has given KTM win No.2

►At the third stop at Angel Stadium last year, KTM earned their first-ever sweep with Ken Roczen winning the 250SX Class

►Since 2000, only three riders (Stewart, Reed and Villopoto) have won the opening race in back-to-back years

►Honda won the opening race of the year in five consecutive seasons (1982-1986)

►Yamaha won the opening race of the year in five consecutive seasons (2000-2004)

►Ryan Villopoto can become only the second rider in history to win four consecutive championships if he wins this year

►Chad Reed and James Stewart are this year racing for their third championships

►Ryan Dungey is this year racing for his second championship