If your're looking for more of an explanation Pete, here's my thinking.

First of all Carina Mia has run three races faster than Songbird has ever run in her life.

Songbird also had to ship cross country for this.

Songbird has been winning by running them off their feet early. It's the 3rd 1/4 to my eye where she does her damage, and then she wins geared down late. The assumption the public tends to make when a horse wins geared down late is that they could have gone faster if asked, but in my experience that is not always - or even usually - the case. Going 6F in 109 and change in a two turn race is really doing some running early. I don't think Songbird could have gone THAT much faster in the end if she had needed to in some of those races. Those were all shorter races too. This is 1 1/8th, a distance Songbird has never gone.

She's also never had to face someone as good as Carina Mia and hold off anyone else that may be coming late. It would probably be really helpful to my bet if the Pletcher filly comes out running early and does some of the early work, which she is fast enough to do, but it's not 100% necessary.

So if you are ever going to take a shot against Songbird, now is probably a decent time IMO. And I chose the Pick 4 pool as the place to do it.

I probably will lose this bet, but to my eye the percentages say it's a good bet to make.