The host breaks down which contestants have impressed him – and which ones are doomed to repeat past mistakes

For a show in its 31st season, Survivor has managed to keep things remarkably fresh and new.

A lot of the credit goes to host Jeff Probst and the producers, who throw in a liberal amount of twists and turns so that contestants never truly know what’s coming. Over the years, we’ve seen tribal swaps, fake merges, hidden immunity idols and double eliminations. (We’re going to pretend that Redemption Island and the outcast twist never happened.)

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But sometimes, the twists are not masterminded by the producers. Contestants have come up with ingenious strategies to change the game.

Probst tells PEOPLE that the game isn’t done evolving and that the second half of the season will mark a new era in Survivor history. Given the aggressive gameplay of this season’s 20 returning contestants, nothing would surprise us.

Can PEOPLE’s own Stephen Fishbach change up the game? In the exclusive preview above, he is plotting with Ciera Eastin to wrestle the game away from the alpha males. With her sneakiness and his strategy, it might just happen.

Below, Probst breaks down the season and tells us which players have impressed him – and which ones haven’t learned from their mistakes.

At this point in the game, what contestants were surprising you with their gameplay?

It’s difficult to answer this in a succinct way given there are so many players playing an impressive game, nearly everyone is really in it to win it. But if I focus on who has surprised me, then that helps a bit.

Let’s go down the list of contestants who are left: Kelley Wentworth.

Kelley been a pleasant surprise. We had high hopes for her in her first season but having a loved one playing alongside is a significant burden because you can’t truly focus on yourself. This season she is playing big and is a contender to go all the way.

Spencer Bledsoe.

He has also impressed as someone who has taken giant steps in trying to change the way he interacts with people.

Ciera Eastin

Ciera has grown a lot since her first time playing. She’s like a sponge. She learns very quickly and is really impressing me with her social game. It’s low-key, but it’s working.

Tasha Fox.

Tasha is playing a much more advanced social game this time; maybe because she has better players around her, but, regardless, she is a threat.

Jeremy Collins.

He’s is in a similar situation to Wentworth – without his wife, he can focus on doing what he intended to do the first time: win $1 million for his family. That clear goal is keeping him grounded, which is key in this game this season.

Andrew Savage.

Savage came in with a chip on his shoulder. He felt he was robbed of his first opportunity, and he wants to rewrite history. I’ve been really impressed with how aggressively he has played and how focused he is on keeping up morale within his alliance.

Keith Nale.

He’s truly impressing me with how good he is at blending in, almost to the point of being invisible. That’s a very tough thing to do. He is just hanging out saying, “Just tell me who to vote for,” and it’s working.

Joe Anglim.

He has a very tough road ahead. He is a physical threat, and everybody knows he is a fan favorite as well. Those two qualities are great in life, but bad on Survivor. But what has impressed me is how good a job Joe is doing in developing relationships so that he doesn’t have to necessarily win every challenge to stay in the game.

Kelly Wiglesworth.

She’s playing a very quiet game. I’m not sure if it’s working or not, but I am surprised because I thought she would come in much more aggressively. She’s doing the opposite. She’s playing an old-school game based on patience and loyalty. These first few tribals post merge will indicate which way this season is going.

Kimmi Kappenberg.

She’s doing a really good job of fitting in and speaking up only when necessary. That has really surprised me. I assumed from the first time she played that she would be much more of a leader, which I don’t think would have worked. She’s put herself in a very nice position.

Stephen Fishbach.

Stephen has surprised me with how determined he is to get Joe out of the game. From my limited information, I don’t understand the rationale and wonder if there is more behind it than just not wanting to lose to another likable jock, like he did in the finals of his season against J.T.

Abi Maria Gomes.

Oh, sweet Abi. I really still root for Abi because I am convinced that she simply does not see how others see her. She sees herself as very rational and believes that most people would agree with her side in any given argument. What has been a pleasant surprise is how many times she tries to turn the other cheek. It rarely gets all the way around but the intention is there.

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A lot of these contestants seem weighed down with the baggage from their first games. Do you think it’s really possible for any of them to play a fresh game?

I don’t know if I agree with that assessment. I think the majority of players have done a really good job of erasing their past and starting a new slate. Maybe I’m the naïve one here, but that’s one of the things that impress me.

But I do understand the question from the standpoint of, “Can you really change your core?” And that is very difficult to do. You can change habits and you can work on how you approach people, things like that. But when you are in extreme conflict and pushed to your limits, your truth comes out and that’s nearly impossible to change. Or so my therapist tells me in my twice weekly sessions.

So is history repeating itself with any of these players?

One of the big reasons Survivor is so compelling is because we love to watch other humans behave. We see ourselves through their actions and we ask, “What would I do in a similar situation?”

I’ve had a lot of beachside chats with our show psychologists, and they always remind me that it’s very hard to change your nature. So as much as #ChaosKass wants to be seen as a calm, reasonable person, the truth is she does have a trigger and when she goes off it’s usually pretty strong. And because she is so intelligent she can weave words that leave people destroyed. Fun to watch and in her nature. I would bet that most of the people in her life say that’s how she is at home, too. Doesn’t mean she’s not lovable, it just means she’s not a pussycat.

Stephen Fishbach is trapped inside a terrible nightmare. Are feelings of inadequacy getting in the way of his otherwise very sharp game play? The stronger, physical guys have always haunted him, and he wants to take down the biggest one so he can erase the demon. My wish for Fishbach would be to give up the ghost and just focus on surviving tribals and not trying to eliminate the big bad wolf.

Abi is sadly, yes, repeating history. I just wish she could see it without taking it personally. But I don’t see that happening over the next several weeks and as a result she is the longest shot to win, which makes her an interesting person to take to the end.

Last week, we saw a lot of tension between Kass and Tasha. What really happened, and what did we miss?

At the core, I think that argument was just two really good players duking it out. Tasha was trying to lure Kass into a false sense of security by implying there might be wiggle room with her regarding her loyalty. When Kass learned it wasn’t true, she tried to use the “lie” Tasha had told her to stir up some trouble. Very good moves on the part of both players. But as we saw, a line was drawn in the sand. Someone was going to win, and someone was going to lose. I LOVE when people play like that. That’s how you win. You have to make moves. The jury has become very tough. They want to see your résumé. So merely hanging out won’t cut it. You have to risk.

Okay, so tease us: What do we have to look forward to in the upcoming weeks?

The game evolves. You will see it slowly birth a new way of approaching relationships. I think fans will enjoy it, and I feel confident this will go down as one of our very best seasons.