Each new season of Big Brother brings a few guarantees: Embarrassing costumes will be worn. The Zingbot will make an appearance. Julie Chen will say, “But first…” about 600 times.

What isn’t guaranteed, though, is whether the houseguests that CBS has cast for the summer will be the strong strategists and entertaining personalities that make 90-something days in the Big Brother house worth watching. And truth be told, the summer reality series has been stuck in a years-long rut; the contestants have been grating, the twists have been half-baked and, all too often, the houseguest that deserves to win has been relegated to second place by a bitter jury. (Sorry, Paul!… twice!)

But Season 20 — which continues tonight at 8/7c — has been a welcome return to form for the competition show, which is in the middle of its most consistently compelling summer in ages, for a few different reasons.

For one, this season’s winner isn’t a foregone conclusion, even after seven weeks of competition. Sure, there are a few formidable houseguests who are better at pulling the strings (hi, Tyler!), and the Level Six alliance is certainly stronger than whatever is left of “FOUTTE.” But the power has ping-ponged between both sides of the house all summer, making it legitimately fun to see who will pull off a Head of Household or Power of Veto win. Throw in the indecisive stragglers like Sam and JC, and every eviction has been a delightfully tense affair.

It helps, too, that Big Brother has introduced twists this season that actually live up to Julie Chen’s annual “This will change the game!” hype. Even if the Power Apps don’t get used, or the BB Hacker doesn’t completely shake up an HOH’s game, these twists have plenty of potential to throw a wrench in someone’s strategy — and it’s given the whole season an undercurrent of unpredictability.

But perhaps the best part of Season 20 has been the sheer volume of delicious, near-Shakespearean drama between the houseguests. Recent seasons of Big Brother have been buzzy for bad reasons, with cast members making headlines for racist, sexist and homophobic comments, among other things. (And, to be clear, some of this summer’s houseguests fall into that category, too.)

Most of this season’s watercooler moments, though, have stemmed strictly from gameplay, and they’ve been nothing short of stunning to watch. There were the heartbreaking 150 seconds where Kaitlyn failed to complete a puzzle that would have kept her in the game. There was Rachel’s utter shock at getting ousted by her own alliance, which led to one of the strangest post-eviction Q&As in the show’s history. And, of course, there was the downfall of Bayleigh, which culminated in an unforgettable screaming match with Tyler.

After nearly two decades on the air, it seemed as though Big Brother had exhausted all of its options to keep the show from going stale, relying instead on anticlimactic twists and the return of unlikable contestants. But the series has gotten its mojo back with a wonderfully wacky Season 20, making it one of summer’s most enjoyable guilty pleasures once again.

Big Brother airs Sundays, Wednesdays and Thursdays on CBS. What are your thoughts on Season 20 so far? Drop ’em in a comment below.