A regenerative furnace having a pair of regenerator ports (110, 130) configured to alternately fire into and exhaust from the furnace, said regenerative furnace comprising an oxy-fuel boost burner (10, 11), said boost burner (10, 11) comprising: at least two burner elements, wherein at least one of the burner elements corresponds to each of the regenerator ports (110, 130) such that a regenerator port (110, 130) and its corresponding at least one burner element are positioned to fire into complimentary regions of the furnace, each burner element comprising: 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 (110, 130) is currently firing and which regenerator port (110, 130) is currently exhausting; to control the second reactant flow to be substantially proportionally distributed to the proportional distribution nozzles; 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 (110, 130) is active and the at least one burner element corresponding to the currently exhausting regenerator port (110, 130) is passive, wherein first reactant flow in the selective distribution nozzle of an active burner element is greater than an average first reactant flow to the selective distribution nozzles and first reactant flow in the selective distribution nozzle of a passive burner element is less than the average first reactant flow to the selective distribution nozzles; wherein the second reactant is substantially proportionally distributed to the proportional distribution nozzles; and wherein the first reactant is one of a fuel and an oxidant and wherein the second reactant is the other of a fuel and an oxidant. at least two burner elements, wherein at least one of the burner elements corresponds to each of the regenerator ports (110, 130) such that a regenerator port (110, 130) and its corresponding at least one burner element are positioned to fire into complimentary regions of the furnace, each burner element comprising: a selective distribution nozzle configured to flow a first reactant; and a proportional distribution nozzle configured to flow a second reactant; and 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 (110, 130) is currently firing and which regenerator port (110, 130) is currently exhausting; to control the second reactant flow to be substantially proportionally distributed to the proportional distribution nozzles; 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 (110, 130) is active and the at least one burner element corresponding to the currently exhausting regenerator port (110, 130) is passive, wherein first reactant flow in the selective distribution nozzle of an active burner element is greater than an average first reactant flow to the selective distribution nozzles and first reactant flow in the selective distribution nozzle of a passive burner element is less than the average first reactant flow to the selective distribution nozzles; to identify which regenerator port (110, 130) is currently firing and which regenerator port (110, 130) is currently exhausting; to control the second reactant flow to be substantially proportionally distributed to the proportional distribution nozzles; 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 (110, 130) is active and the at least one burner element corresponding to the currently exhausting regenerator port (110, 130) is passive, wherein first reactant flow in the selective distribution nozzle of an active burner element is greater than an average first reactant flow to the selective distribution nozzles and first reactant flow in the selective distribution nozzle of a passive burner element is less than the average first reactant flow to the selective distribution nozzles; wherein the second reactant is substantially proportionally distributed to the proportional distribution nozzles; and wherein the first reactant is one of a fuel and an oxidant and wherein the second reactant is the other of a fuel and an oxidant.