To start off, I'll talk about this race in general and the track it's ran on, some thoughts on mile and a half races, and why running all 3 legs of the triple crown is so grueling.
The Belmont stakes is called the test of champions for a reason. The race is long, grueling and requires a talented horse and rider. Belmont park is called the "big sandy" for a reason as well. It has this deep sandy dirt that some horses don't like and other relish. Lemon Drop Kid loved the surface the year he took the crown away from Charismatic. An angle to play is to look for horses that have run well over the Belmont surface, and horses who's parents have run well over the surface.
One major thing to remember is that the Belmont stakes does not favor deep closers. Remember this. Deep closers do not need more time to catch the leaders. They need faster fractions to wear out the horses near the pace. No horse has run the last 5 runnings of the Belmont from further back than 3rd at the top of the stretch. Generally, there is no pressure on the lead horse, and the race sets up like it did last year where the lead horse holds on. Remember, Alydar and Affirmed ran neck and neck in front for the last 6 furlongs because there was no pace.
Deep closers win races when the pace is really fast. The best example I can think of for this was the year Monarchos won the Kentucky Derby. The track was packed very fast, and Songandaprayer was a true sprinter running in the derby pretty much because he could. He set the fastest fractions in Kentucky Derby history, and tired out all the stalkers. Talented horses like Point Given just faded in the stretch and Monarchos came out of nowhere to win in near record time. That's what needs to happen for a deep closer to win a race like this.
Another thing to consider is how grueling 3 races in 5 weeks is for horses. Horses have become both faster and more fragile in recent years. Whether that is due to inbreeding, coddling young horses, or whatever else people say, it's here and it must be accounted for. Because horses have become so much more fragile, it's very likely that they will not run up to their best after 2 big races in a month. That's why a lot of trainers skip the Preakness and train their horse for the Belmont. This only affects 2 of the horses in the race, and one is a toss anyway, but a very close look at Mine That Bird is needed in this race.