No, there are two percentages on fivethirtyeight, one saying if the election were held today, Trump would win 57% - the other attempts to measure the probability Trump will win in November - 48%.
Personally, I would place far more credence in the “who would you vote for if the election were held today” poll - at least it is based on polling. The probability model is worthless if you think about it.
I mean, statistically, you can say things like “the incumbent party candidate has won 65% of the elections when unemployment was below 6% and the non incumbant party candidate is not taller than the incumbant party candidate, except during war time”.
But these kinds of concocted generalizations only work in retrospect.
Oops. 48% should be 40.8%