An oxy-fuel boost burner for a regenerative furnace having a pair of regenerator ports configured to alternately fire into and exhaust from the furnace, including at least one burner element corresponding to each of the regenerator ports by being positioned to fire into a complimentary region of the furnace, each burner element including a selective distribution nozzle configured to flow a first reactant and a proportional distribution nozzle configured to flow a second reactant, and a controller programmed to identify which regenerator port is currently firing and which is currently exhausting and to independently control the first reactant flow to each selective distribution nozzle such that the at least one burner element corresponding to the currently firing regenerator port has a greater than average first reactant flow and the at least one burner element corresponding to the currently exhausting regenerator port as a less than average first reactant flow.