CNN officially announced the lineup for the second Democratic debates Thursday—and it's already shaping up to be an interesting two nights. After June debates that pitted former Vice President Joe Biden against Senator Bernie Sanders—and, memorably, Sen. Kamala Harris—while Sen. Elizabeth Warren had a night with the spotlight to herself, CNN's three-tier system ensured that the top four frontrunners would be divided evenly over the two evenings. And the resulting matchups will certainly be worth watching, as Warren and Sanders face off on Tuesday, July 30 while Biden and Harris meet once again on Wednesday, July 31.

In an effort to ensure transparency, CNN chose the debate lineup live on-air, with anchors pulling names out of boxes as cameras loomed overhead. Unlike the two candidate tiers used by NBC for the first debate—resulting in nearly all of the frontrunners getting clumped together in the second night—CNN divided candidates up into three different groups based on their current rankings in the polls. Along with Warren and Sanders, the first debate night will include Mayor Pete Buttigieg, former Rep. Beto O'Rourke, Sen. Amy Klobuchar, Rep. Tim Ryan, former Gov. John Hickenlooper, former Rep. John Delaney, author Marianne Williamson, and Gov. Steve Bullock, who is making it on to the debate stage for the first time. The second night will feature Sen. Cory Booker, former Mayor Julián Castro, entrepreneur Andrew Yang, Sen. Kirsten Gillibrand, Sen. Michael Bennet, Gov. Jay Inslee, Rep. Tulsi Gabbard, and Mayor Bill de Blasio, in addition to Harris and Biden.

Tuesday night will be most notable for the match-up against Warren and Sanders, who are pitted against each other for the first time after taking pains to assert their friendship on the campaign trail. “We just don’t attack each other,” Warren said on the California Nation podcast earlier in July. “Bernie’s been my friend forever, and I’ve been his friend forever.” Whether or not their aversion to attacks holds true, the two going head to head will likely be useful for the candidates to distinguish themselves from each other after continually getting lumped together as two sides of the same progressive coin. The debate should give the senators the chance to expose the differences in their agendas, giving voters clarity on how the two noted progressive's platforms stand apart. “Grateful for another chance to talk about our grassroots movement at CNN’s Democratic presidential debate on July 30th,” Warren tweeted Thursday. “I’m fired up for big, structural change—let’s do this!” While the Warren/Sanders match-up ensures the debate night will be a banner moment for progressive policies, many of the other candidates in the Tuesday night match-up, like Klobuchar and Buttigieg, are far more moderate, giving them a chance to distinguish themselves from the frontrunners in the spotlight. For Buttigieg, standing next to the 77-year-old Sanders will also give him the perfect opportunity to visually emphasize his message of “generational change,” a point the millennial mayor has been quick to highlight in his campaign.

Wednesday night will put a target on frontrunner Biden's back once again—particularly as he stands next to Booker and Harris, who have had perhaps the most vocal disagreements with Biden in the campaign thus far. The debate night will mark the first match-up between Biden and Booker, who previously scuffled after the former vice president claimed the New Jersey senator should “apologize” for being offended by Biden's comments on fraternizing with segregationists. Booker has continued to speak out against Biden, paving the way for a likely argument on the debate stage. When asked Thursday whether he felt disrespected by Biden dismissing his comments about the segregationists, Booker responded, “Of course I did.” “How many times have we all in our lives, who are some kind of ‘other,’ dealt with mansplaining or dealt with condemning remarks?” Booker said, adding that the Democratic Party does not need a nominee who would “fall into a defensive crouch and try to shift blame.” “I'm happy that he came forward and apologized, but a presidential nominee shouldn't need that kind of lesson,” Booker continued.