Acknowledging the cheers of a large Bank Holiday crowd, Dettori said: "Just 199 more to go and I've got the double century."
Dettori is quoted as 11-10 favourite to retain his title which this year will be calculated on prize-money won rather than the number of winners. Looking in good shape after a two-week holiday in Morocco, he said: "I am hoping to have another good season, but I am not going to say I am going to win the title again.
"I arrived back on Friday after spending Christmas with my mum and dad in Morocco and I am feeling fit and well.
"The weather's chilly but I am looking forward to it all again - and I hope I've still got it."
He would not be drawn on the controversy over the new way of calculating the jockeys' title. "I've come here because I love riding. All I want to do is ride winners," he said.
nToday's meeting at Edinburgh has gone the same way as yesterday's cards at Ayr, Cheltenham and Windsor and succumbed to frost and snow. A total of 20 meetings have now been abandoned during this National Hunt season, but warmer weather is predicted for later in the week.