From summer 1918 to summer 1919, the Bolsheviks were on the brink of collapse in Russia. In the east, the Whites under Krasnov had conquered Kazan with the treasure of the Bolsheviks; in the south, Denikin had taken Orel and was marching towards Tula. The Bolsheviks already considered giving up Petrograd to be able to defend Moscow.
However, the Whites made strategical mistakes. Krasnov especially had most of his forces at the northern front, hoping to join the army of general Miller, who operated from Archangel. His center and the south were too weak.
What if Krasnov had attacked in the south instead? This would have allowed the Whites in the East and South respectively to join forces.