What is a split-seconds chronograph?A split-seconds chronograph or 'rattrapante' is a type of chronograph watch with two coaxial superimposed center-seconds hands that are controlled by two push-buttons. One push-button controls the split-seconds hand to stop or join the chronograph hand. The other push-buttons control both the hands and all of the functions of the chronograph. The two hands, the chronograph hand and the split-seconds hand, are used for timing several events that start simultaneously but are of different durationsTo operate the split-seconds chronograph, both hands are started and remain superimposed. Then at the end of the first duration, the split-seconds hand can be stopped while the chronograph hand continues to move. The duration of the first event can be read. After recording, the split-seconds hand can be released to instantly move and join the chronograph hand, synchronizing with it and thus ready for another recording. At the end of each event the hands can be stopped and then returned to zero.The split-seconds chronograph, in its present form, was first introduced in 1880. Split-seconds chronograph wristwatches came on the market circa 1922 by Patek Philippe (the first known wristwatch of this kind was Patek Philippe No. 124824, case no. 235326, which was sold by Antiquorum as lot 448 on November 14, 1999 for US $ 1,918,387, which is the highest price ever realized for a wristwatch at auction). This wristwatch appeared five years prior to the official release of the split-seconds chrnograph, making Patek Philippe the first manufacture to create this model. As they require a complicated and technical mechanism, these watches are desirable, very collectible and extremely difficult to make which accounts for their rarity.