As with all Pokémon games, another key aspect of Pokémon is evolving them into their later forms. In Pokémon Pinball, you can only capture the lowest evolved Pokémon so you have to use Evolution Mode in order to fill up the rest of your Pokédex. To access Evolution Mode, you need to go up the leftmost passage of the table, going clockwise, three times. Doing so will activate access to a tunnel, in Red it's guarded by Ditto while in the Blue Table, it's just accessed via Slowpoke. Once activated, you are given two minutes in order to evolve your Pokémon.
On the table, you will get arrows to variou parts of the table. What you need to do is hit these parts in order to access the evolution items. However, only three of these arrows will give you access to these items with the others making your Pokémon tired thus preventing you from getting any other bits for a five seconds. Successfully hit an area and an item will appear somewhere on the table, requiring you to have to pass through it to access it.
These items all match the Pokémon's method of evolutions in the game and don't require any particular extra calculations to get the right item, so it is fairly straight forward. Obtain three of these items and your Pokémon will automatically evolve
There is another perk through the Evolution Mode. If you select a Pokémon that is already fully evolved, you will go through the same mechanics, obtaining the EX marks to give the Pokémon experience. However, since the Pokémon cannot evolve, you get something else. This time, you'll just receive a massive point bonus: 10,000,000 points.