Solar series 142 and 147 started same year - series 147 and 152 will be ending same year. Why? Coincidence?
The reason Saros Cycles begin and end is down to the positions of the orbits of the Sun, the Moon and the Earth. From the main Wikipedia page on Saros:
For an eclipse you need the 3 bodies to line up at a full or new moon,

and repeat occurrences of these lunar phases result from solar and lunar orbits producing the Moon's synodic period of 29.53059 days...however for the majority of these, the shadow of the Earth or Moon fall to the north or south of the other body.

It can only happen when a full or new moon is around the ecliptic.

The period of time for two successive lunar passes through the ecliptic plane (returning to the same node) is termed the draconic month, a 27.21222 day period. The three-dimensional geometry of an eclipse, when the new or full moon is near one of the nodes, occurs every 5 or 6 months when the Sun is in conjunction or opposition to the Moon and coincidentally also near a node of the Moon's orbit at that time, or twice per eclipse year.

Also:

Two Saros eclipses have the same appearance and duration due to the distance between the Earth and Moon being nearly the same for each event because the Saros eclipse cycle is also an integer of the anomalistic month, the period of the eccentricity of lunar orbit, 27.5545 days.
After one saros, the Moon will have completed roughly an integer number of synodic, draconic, and anomalistic periods (223, 242, and 239) and the Earth-Sun-Moon geometry will be nearly identical

The reason we get varying start and ends is because of this. Those roughly integer periods vary.
This diagram from that Wikipedia page illustrates perfectly why they can be different lengths, stop and start at changing intervals etc.