Jockey Glen Boss rides the Australian mare Makybe Diva to her 3rd consecutive Melbourne Cup win at Flemington Racecourse in Melbourne. November 1, 2005. REUTERS/David Callow 

Jockey Glen Boss rides the Australian mare Makybe Diva to her third consecutive Melbourne Cup win at Flemington Racecourse in Melbourne November 1, 2005. REUTERS/David Callow 

Trainer Lee Freedman (L) and owner Tony Santik carry Jockey Glen Boss after the mare Makybe Diva won her third consecutive Melbourne Cup at Flemington Racecourse in Melbourne November 1, 2005. REUTERS/David Callow 

Owner Tony Santik carries winning Jockey Glen Boss after Australian mare Makybe Diva won their third consecutive Melbourne Cup at Flemington Racecourse in Melbourne November 1, 2005. REUTERS/David Callow 

Jockey Glen Boss rides the Australian mare Makybe Diva into the mounting yard after winning third consecutive Melbourne Cup at Flemington Racecourse in Melbourne November 1, 2005. REUTERS/David Callow 

Trainer Lee Freedman (L) and owner Tony Santik (R) carry jockey Glen Boss in celebration after the Australian mare Makybe Diva won her 3rd consecutive Melbourne Cup at Flemington Racecourse in Melbourne November 1, 2005. REUTERS/David Callow 

Trainer Lee Freedman (L) and owner Tony Santik carry Jockey Glen Boss after the mare Makybe Diva won her third consecutive Melbourne Cup at Flemington Racecourse in Melbourne November 1, 2005. REUTERS/David Callow 

Jockey Glen Boss celebrates on horse Makybe Diva as he returns to scale after winning the Melbourne Cup at Flemington race course November 2, 2004. Makybe Diva won Tuesday's 144th running of the A$4.6 million (US$3.5 million) Melbourne Cup to become only the fourth horse and the first mare to capture Australia's richest and most famous race two years in a row. REUTERS/David Callow DC/CP 

Jockey Glen Boss (C) celebrates on horse Makybe Diva as he returns to scale after winning the Melbourne Cup at Flemington race course November 2, 2004. Makybe Diva won Tuesday's 144th running of the A$4.6 million (US$3.5 million) Melbourne Cup to become only the fourth horse and the first mare to capture Australia's richest and most famous race two years in a row. REUTERS/David Callow DC/CP 

Jockey Glen Boss on horse Makybe Diva passes the winning post to win the Melbourne Cup at Flemington, November 2, 2004. Makybe Diva won Tuesday's 144th running of the A$4.6 million (US$3.5 million) Melbourne Cup to become only the fourth horse and the first mare to capture Australia's richest and most famous race two years in a row. REUTERS/David Callow Pictures of the month November 2004 DC/SH 

Jockey Glen Boss celebrates on horse Makybe Diva as he returns to scale after winning the Melbourne Cup at Flemington race course November 2, 2004. Makybe Diva won Tuesday's 144th running of the A$4.6 million (US$3.5 million) Melbourne Cup to become only the fourth horse and the first mare to capture Australia's richest and most famous race two years in a row. REUTERS/David Callow DC/CP 

Jockey Glen Boss celebrates on horse Makybe Diva as he returns to scale after winning the Melbourne Cup at Flemington race course November 2, 2004. Makybe Diva won Tuesday's 144th running of the A$4.6 million (US$3.5 million) Melbourne Cup to become only the fourth horse and the first mare to capture Australia's richest and most famous race two years in a row. REUTERS/David Callow DC/CP