We study the problem of testing discrete distributions with a focus on the high probability regime. Specifically, given samples from one or more discrete distributions, a property $\mathcal{P}$, and parameters $0< ε, δ<1$, we want to distinguish {\em with probability at least $1-δ$} whether these distributions satisfy $\mathcal{P}$ or are $ε$-far from $\mathcal{P}$ in total variation distance.…