A method for controlling an operating point of a gas turbine that includes a compressor, a combustor and at least a turbine, the method comprising: determining an exhaust pressure drop at an exhaust of the turbine; measuring a compressor pressure discharge at the compressor; determining a turbine pressure ratio based on the exhaust pressure drop and the compressor pressure discharge; calculating a primary to lean-lean mode transfer threshold reference curve as a function of the turbine pressure ratio, wherein the primary to lean-lean mode transfer threshold curve includes points at which an operation of the gas turbine is changed between a primary mode and a lean-lean mode; determining at a first time when a turbine exhaust temperature associated with the operating point is higher than an exhaust temperature of the primary to lean-lean mode transfer threshold reference curve for the same turbine pressure ratio; and changing, after a predetermined time after the first time, a split fuel quantity from a first value to a second value if the exhaust temperature associated with the operating point remains higher than the exhaust temperature of the primary to lean-lean mode transfer threshold reference curve, wherein the primary mode is defined as providing more than half of the fuel to primary burners and providing a remaining or no fuel to a secondary burner of the combustor and also igniting the provided fuel in a primary region of the combustor, the primary region being adjacent to a secondary region, the lean-lean mode is defined as providing fuel to both the-primary burners and the secondary burner and burning the provided fuel both in the primary region and the secondary region, and the split fuel quantity describes in percentages a first amount of the total fuel that is received by the primary burner and a second amount of the total fuel that is received by the secondary burners. determining an exhaust pressure drop at an exhaust of the turbine; measuring a compressor pressure discharge at the compressor; determining a turbine pressure ratio based on the exhaust pressure drop and the compressor pressure discharge; calculating a primary to lean-lean mode transfer threshold reference curve as a function of the turbine pressure ratio, wherein the primary to lean-lean mode transfer threshold curve includes points at which an operation of the gas turbine is changed between a primary mode and a lean-lean mode; determining at a first time when a turbine exhaust temperature associated with the operating point is higher than an exhaust temperature of the primary to lean-lean mode transfer threshold reference curve for the same turbine pressure ratio; and changing, after a predetermined time after the first time, a split fuel quantity from a first value to a second value if the exhaust temperature associated with the operating point remains higher than the exhaust temperature of the primary to lean-lean mode transfer threshold reference curve, wherein the primary mode is defined as providing more than half of the fuel to primary burners and providing a remaining or no fuel to a secondary burner of the combustor and also igniting the provided fuel in a primary region of the combustor, the primary region being adjacent to a secondary region, the lean-lean mode is defined as providing fuel to both the-primary burners and the secondary burner and burning the provided fuel both in the primary region and the secondary region, and the split fuel quantity describes in percentages a first amount of the total fuel that is received by the primary burner and a second amount of the total fuel that is received by the secondary burners.