If you select "Create (1:1) price combo" in the Combo Selection window of TWS, the price of the combo is displayed as if it were a 1:1 price combo regardless of the legs ratio.
For example: if you create a 2:1 legs ratio spread with "Create (1:1) price combo" selected, ticker row prices will be displayed as if it were a 1:1 leg ratio spread.
Please Note: Although the order will be submitted for the legs ratio chosen upon combo creation regardless of "Create (1:1) price combo" set up, if "Create (1:1) price combo" is selected it is possible that fewer order types will be available.
More information on using the Combo Selection window can be found in our Users' Guide.