Method for determining a fuel split setting value utilisable for adjusting a fuel split setting for a combustion device, the fuel split setting defining a relation between main fuel provided at primary fuel injection points and pilot fuel provided at at least one secondary fuel injection point, both being supplied to the combustion device for being combusted to a combusted fluid, particularly both having the same chemical composition, particularly both being a gaseous fuel, the method comprising the steps of: - retrieving a first information item correlated to a heating value of supplied main fuel; - retrieving a second information item correlated to a combustor operating condition when combusting the main fuel and the pilot fuel, the second information item being particularly at least one of a firing temperature, an exit temperature of the combusted fluid exiting the combustion device, thrust of the combusted fluid, and an engine load of a rotating machine downstream of the combustor device and driven in response of a flow of the combusted fluid, particularly a gas turbine engine; - retrieving at least one third information item, the third information item representing stability of combustion in the combustion device, particularly representing at least one of combustion dynamics pressure, emission of NOx, emission of CO, combustion device surface temperature, combustion dynamics noise emission, vibration of the combustion device, and flame instability; - selecting a predefined pair of minimum and maximum boundary curves (100A, 100B; 100A', 100B';...) for the fuel split setting from a plurality of predefined pairs of boundary curves (100A, 100B; 100A', 100B';...) based on the first information item and the second information item, the minimum and maximum boundary curves (100A, 100B; 100A', 100B';...) defining a band of fuel split settings permitted for a range of second information item values, the bands (100, 100', 100", and 100''') each are preset for a given Wobbe Index range of the fuel and the Wobbe Index range defines a range of allowable heating values for the supplied fuel; - determining the fuel split setting value within the selected pair of minimum and maximum boundary curves (100A, 100B; 100A', 100B';...) based on the third information item, wherein the determined fuel split setting value being utilisable for adjusting the fuel split setting for the combustion device. - retrieving a first information item correlated to a heating value of supplied main fuel; - retrieving a second information item correlated to a combustor operating condition when combusting the main fuel and the pilot fuel, the second information item being particularly at least one of a firing temperature, an exit temperature of the combusted fluid exiting the combustion device, thrust of the combusted fluid, and an engine load of a rotating machine downstream of the combustor device and driven in response of a flow of the combusted fluid, particularly a gas turbine engine; - retrieving at least one third information item, the third information item representing stability of combustion in the combustion device, particularly representing at least one of combustion dynamics pressure, emission of NOx, emission of CO, combustion device surface temperature, combustion dynamics noise emission, vibration of the combustion device, and flame instability; - selecting a predefined pair of minimum and maximum boundary curves (100A, 100B; 100A', 100B';...) for the fuel split setting from a plurality of predefined pairs of boundary curves (100A, 100B; 100A', 100B';...) based on the first information item and the second information item, the minimum and maximum boundary curves (100A, 100B; 100A', 100B';...) defining a band of fuel split settings permitted for a range of second information item values, the bands (100, 100', 100", and 100''') each are preset for a given Wobbe Index range of the fuel and the Wobbe Index range defines a range of allowable heating values for the supplied fuel; - determining the fuel split setting value within the selected pair of minimum and maximum boundary curves (100A, 100B; 100A', 100B';...) based on the third information item, wherein the determined fuel split setting value being utilisable for adjusting the fuel split setting for the combustion device.