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 pushbutton controls the split-seconds hand to stop or join the chronograph hand. The other pushbuttons control both hands and all the functions of the chronograph. The chronograph hand and the split-seconds hand are used for timing several events that start simultaneously, but are of diffrent durations. To operate the splitseconds chronograph, both hands are started and remain superimposed. 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 then be read. After recording, the split-seconds hand can be released to instantly join the chronograph hand, synchronizing with it and thus being ready for another recording. At the end of each event the hands can be stopped and returned to zero. The split-seconds chronograph, in its present form, was introduced in 1880. Split-seconds chronograph wristwatches were placed on the market circa 1922 by Patek Philippe (the first known wristwatch of this kind was Patek Philippe No. 124824, case no. 235326, sold by Antiquorum as lot 448 on November 14, 1999.) This timepiece appeared five years prior to the official release of the split-seconds chronograph, making Patek Philippe the first manufacture to create this complication in a wristwatch. As they require a highly complicated mechanism, these watches are desirable, very collectible and extremely difficult to produce, accounting for their rarity.