Until the beginning of the 1960s, tractors had a single register of gears, hence one gear stick, often with three to five forward gears and one reverse. Then, group gears were introduced, and another gear stick was added. Later, control of the forward-reverse direction was moved to a special stick attached at the side of the steering wheel, which allowed forward or reverse travel in any gear. Nowadays, with CVTs or other clutch-free gear types, fewer sticks control the transmission, and some are replaced with electrical switches or are totally computer-controlled.