The Pulse Newsletter 📣 | This is The Athletic’s daily sports newsletter. Sign up here to receive The Pulse directly in your inbox. Good morning! I hope your ping pong ball works out tonight. We are in the thicket now. Second-round series have become slogs, and I mean that as a compliment. Everyone’s hands are muddy. Time to find out who has the mettle to push through. Which means it’s a perfect time for our favorite bit, It’s So Over/We’re So Back, for all our playoff action last night: It’s So Over: Pacers 129, Cavaliers 109. This was jaw-dropping, with Indiana up by…