Fast winning strategies for Staller in the Maker-Breaker domination game

TL;DR

This paper investigates the Staller winning strategies in the Maker-Breaker domination game on graphs, introducing new parameters to measure minimal moves needed for Staller to win under various conditions.

Contribution

It introduces the parameters _{ m SMB}(G) and '_{ m SMB}(G), analyzes their properties, and provides exact formulas for specific graph classes.

Findings

'_{ m SMB}(G) _{ m SMB}(G)  (G) always satisfy (G)+1  '_{ m SMB}(G)  _{ m SMB}(G).

For any integers r,s,t with 2  r  s  t, there exists a graph G with (G)=r, '_{ m SMB}(G)=s, and _{ m SMB}(G)=t.

Exact formulas are provided for '_{ m SMB}(G) when G is a path or a tadpole graph.

Abstract

The Maker-Breaker domination game is played on a graph $G$ by two players, called Dominator and Staller, who alternately choose a vertex that has not been played so far. Dominator wins the game if his moves form a dominating set. Staller wins if she plays all vertices from a closed neighborhood of a vertex $v \in V(G)$. Dominator's fast winning strategies were studied earlier. In this work, we concentrate on the cases when Staller has a winning strategy in the game. We introduce the invariant $\gamma'_{\rm SMB}(G)$ (resp., $\gamma_{\rm SMB}(G)$) which is the smallest integer $k$ such that, under any strategy of Dominator, Staller can win the game by playing at most $k$ vertices, if Staller (resp., Dominator) plays first on the graph $G$. We prove some basic properties of $\gamma_{\rm SMB}(G)$ and $\gamma'_{\rm SMB}(G)$ and study the parameters' changes under some operators as taking the disjoint union of graphs or deleting a cut vertex. We show that the inequality $\delta(G)+1 \le \gamma'_{\rm SMB}(G) \le \gamma_{\rm SMB}(G)$ always holds and that for every three integers $r,s,t$ with $2\le r\le s\le t$, there exists a graph $G$ such that $\delta(G)+1 = r$, $\gamma'_{\rm SMB}(G) = s$, and $\gamma_{\rm SMB}(G) = t$. We prove exact formulas for $\gamma'_{\rm SMB}(G)$ where $G$ is a path, or it is a tadpole graph which is obtained from the disjoint union of a cycle and a path by adding one edge between them.