Found it when I wasn't looking.
Study done on the fav
12539 wins by the fav were followed by a loss.
3445 wins were followed by another win ie 2 in a row
462 wins were followed by a second win ie 3 in a row
50 wins were followed by a third win ie 4 in a row
3 wins were followed by a fourth win Ie 5 in a row
1 win was followed by a fifth win Ie 6 in a row.

I don't the sample size but it has to be circa 50,000. using the standard adage of the fav winning a third of their starts. Thus the sample size is enough to be consistently applied to everyday racing.

What you can take from this is that it is easier to lose than win, It is easier to string losses together than to string wins together. Multiple wins are a very rare breed. Beton