Finish with the league's worst record and you're not guaranteed the No. 1 pick — you're just guaranteed the best odds at it. That's the part that confuses newer fans most about the WNBA draft lottery: it's a weighted random drawing among the teams that missed the playoffs, not a straight ranking by record.
Every team that doesn't make the playoffs is entered into the lottery pool. Instead of using just that one season's record, the WNBA weights the odds using each team's cumulative record over the past two seasons — a team that's been bad for two years running gets a stronger claim on the top pick than a team that just had one rough year.
The worst two-year record gets the best odds at the No. 1 pick, but "best odds" isn't "certain odds" — it's still a drawing, so the top overall selection can and does go to a team that wasn't actually the league's worst. That built-in uncertainty is deliberate: a lottery with real randomness gives teams less incentive to lose games on purpose late in the season chasing the top pick, since losing doesn't lock anything in.
The lottery is decided by a ping-pong ball drawing — a physical randomization, not a computer draw — which determines the No. 1 and No. 2 overall picks specifically. The rest of the lottery-team picks (3rd, 4th, and on down) are then filled in based on each team's cumulative record over the prior two seasons, worst to best. Once the lottery slots are set, the remaining first-round picks go to the teams that did make the playoffs, in reverse order of how they finished — so the team that lost in the first round picks ahead of a team that made the Finals.
The lottery is one of the clearer examples of a league actively trying to keep parity in place. Combined with a hard salary cap under the new CBA, a rebuilding team's fastest path back to competitive isn't outspending anyone — it's drafting well, which is exactly what the lottery is designed to give losing teams a real, if not guaranteed, shot at.