"After seven savage laps, those who managed not to be upended or killed and finish in the top three took home prizes," wrote Struck.
Experienced charioteers drove hard-to-manage chariots driven by four or even more horses.
Their sporting equipment included a leather helmet, shin guards, chest protector, a jersey, a whip, and a sharp knife with which to cut the reins if the chariot overturned.
Although drivers did not have their helmets or whips blessed by generous sponsorship, they could rely on stables or factions, basically teams similar to today's Formula One: the Reds, Greens, Blues and Whites.
"The drivers affiliated with teams supported by large businesses that invested heavily in training and upkeep of the horses and equipment," said Struck.
Diocles won his first race two years after his debut with the Whites, four years later, he briefly moved with the great rivals the Greens. But had the most success with the Reds, with whom he remained until the end of his career at the age of "42 years, 7 months, and 23 days."
He is said to have won 1,462 of his 4,257 races and finished second 861 times, making nine horse "centenari" (100-time winners) and one horse, Pompeianus, a 200-time winner.
The inscription details his winning tactics: he "took the lead and won 815 times," took the competitors by surprise by "coming from behind and winning 67 times," and "won in stretch 36 times."
Although other racers surpassed him in the total number of victories - a driver called Pompeius Musclosus collected 3,599 winnings - Diocles became the richest of all, as he run and won at big money events. For example, he is recorded to have made 1,450,000 sesterces in just 29 victories.
Struck calculated that Diocles' s total earnings of 35,863,120 sesterces were enough to provide grain for the entire population of Rome for one year, or to fund the Roman Army at its height for more than two months.
"By today's standards that last figure, assuming the apt comparison is what it takes to pay the wages of the American armed forces for the same period, would cash out to about $15 billion," wrote Struck.
"Even without his dalliances, it is doubtful Tiger could have matched it," he added.
Photo: Winner of a Roman chariot race; Wikipedia Commons