The next stop on the Grand Slam Track schedule takes fans and athletes to the Ansin Sports Complex in Miramar, Florida, just outside of Miami. Barring injury, you can bank on all of the league’s Racers to be there. But they’ll comprise just half the fields in each event. That’s where the Challengers—athletes who drop in for an à la carte Slam—come in.

While it seems fair to assume that the strategy behind sending out Challenger invites cascades downwards from “if you’re the fastest non-Racer available, welcome aboard,” there’s likely a bit more thought and strategy to it. And with the first round of Challenger announcements for Miami officially out there, we’re able to guess at how GST hopes these athlete inclusions will make for even more compelling matchups and racing. Here are a few of our thoughts:

Timothy Cheruiyot, Bridging the Divide in the Men’s Short Distance

We learned in Kingston that Emmanuel Wanyonyi has the strength to mix it up in—at least—a tactical 1500m against the best milers on the planet. Those milers collectively and understandably aren’t global championship sharp yet. And while we can expect them to improve with every Slam, right now, they aren’t likely to go out with a Marco Arop-set pace in the 800m. Adding Cheruiyot to the mix should help close the gap between specialties. He’s not just a former World champ over 1500m and the owner of a sub-1:44 800m PB… it’s his fearlessness as a racer that is compelling. It was Cheruiyot who pulled the eventual medalists back to Jakob Ingebrigtsen in the Paris final—he will willingly go after whoever’s in the lead, of whatever race he’s in. That’s valuable in a setting like GST!

Anna Hall Knows How to Double (and Beyond) in the Women’s Long Hurdles

Rounding the oval in pursuit of Sydney McLaughlin-Levrone is hard enough. Running two brutal races against her in one weekend? That’s just brutal. Cue: heptathlete Anna Hall, who is no stranger to grueling competition schedules. She’s no slouch over hurdles, and could sneak up on some of the 400m hurdles specialists there. But it’s her chops in the flat 400m—and her proven ability to put up high-level performances when heavily fatigued—that’ll make her an even bigger factor on her second day of racing. We’re not saying she’s going to run down McLaughlin-Levrone, but leave it to a heptathlete with notable 800m strength to at least make things interesting. GST is fortunate to have the elusive SML on board, because whenever she lines up, it’s appointment viewing. The hard part is making what can easily become two largely solo efforts into unique spectator events.

Amber Anning Might Be the Perfect Spoiler in the Women’s Long Sprints

In one of the most exciting categories from Kingston, fans were treated to a showdown between Gabby Thomas, Marileidy Paulino, and Salwa Eid Naser. Paulino and Naser are the two best 400m specialists out there right now, but Thomas can mix it up over a full lap, too, as demonstrated in Jamaica. In Anning, this group gets yet another versatile, world-caliber star who will undoubtedly be in the hunt for a top-three placement in the 400m and should be the field’s best bet to upset Thomas in the 200m. The name of the game for GST is unexpected outcomes, and by introducing one more potential spoiler to this elite crew, we could see an outcome where one of the greatest 400m runners ever in Paulino or Eid Naser doesn’t even land in the group’s top-three. How’s that for an unexpected outcome?

For more of the top stories and analysis from the biggest stories in track and field from the past week, subscribe to The Lap Count newsletter for free. New edition every Wednesday morning at 6:00 a.m. ET.