We consider both the backtrack and non-backtrack versions of the robber locating game on a simple finite connected graph where a cop wants to locate an invisible mobile and omniscient robber using distance queries. Also an adaptive sequential version of the metric dimension problem, referred as the sequential locating game, has been studied where the robber is invisible, but immobile and the cop’s objective is to locate the robber by distance queries. So far there is no known lower bound for location number, i.e., the minimum number of rounds taken by the cop to win in the robber locating game, of any locatable graph except trees, irrespective of a backtracking or non-backtracking robber, up to the best of our knowledge. The same is true for the lower bound of sequential location number which is the minimum number of rounds taken by the cop to win in the sequential locating game. In this article, we show that the lower bound of location number for any locatable graph G with maximum degree \(\varDelta \) is \(\lceil \log _2 \varDelta \rceil \) , irrespective of a backtracking or a non-backtracking robber. We also show that there are infinitely many graphs with \(\varDelta =3\) for which the lower bound is tight for both the backtrack and non-backtrack versions. Furthermore, we prove that the lower bound for sequential location number is \(\lceil \log _3(\varDelta +1)\rceil \) . This bound is tight for \(\varDelta =3^m\) , \(m\ge 1\) being any positive integer. Interestingly, this provides us with a difference between the lower bounds of location numbers (both backtrack as well as non-backtrack) and sequential location number by a linear multiplicative factor (of \(\log _2 3 \approx 1.585\) ).