Picked up my second EM this past weekend - a 1971 Gottlieb Playball.

It's cosmetically dirty, but looks like it will clean up fairly well. New rubbers, and a few other odds and ends ordered and en route.
To my untrained eye - it seems mechanically pretty close to working right, but there are a few things that I've noticed wrong.
Side note - a copy of the schematic was in the coinbox. A copy of the manual is coming from PBR.

The score and runs reels all reset to zero at game start, and the ball launches when the right flipper is pressed. No issues there.
Every switch on the playfield scores points on the score reels as they should (Well I assume the amounts are right.), and every score reel increments the next reel over when going from 9 to 0.

The obvious issue to my eye is the base runners in the center of the playfield.
If I understand the game right - the home plate light is always lit. Makes sense.

Here's where I'm having trouble troubleshooting - I'm not exactly clear on how things are supposed to work.
I've been watching this video of someone playing the add-a-ball version to help me sort things out.

Of course I have no idea if the machine in this video is working 100%.

This is how I think it's supposed to work - if someone sees anywhere where I'm wrong - please let me know.

- Game starts, bases are empty (unlit) with only home plate's light on.
- The lights next to the various numbered stand up targets should all be lit.
- Hitting a lit stand up is the equivalent of getting the corresponding hit. 1 for a single, 2 for a double, 3 for a triple.
- There are also rollover switches that correspond to various hits. Triples in the upper corners, doubles on the sides, singles for the in lanes, and homeruns for the out lanes.
- Lastly, there's the two vari targets with their value/hit level depending on how hard they're hit.
- Upon scoring a hit via any means, the lights for any stand up matching that hit will go off.
- Rolling over one of the single/double/triple rollover switches will also turn off the lights for the similarly valued stand ups.
- Getting a hit lights the light for the corresponding base, with any existing lit bases advancing as well.
ie - if you have a man on second and hit a single, the runner on second will move to third and the batter is on first. 1st and 3rd lights lit.
- Obviously, as a light advances to home, a run scores.

Some questions
Am I right regarding how the runners should advance? ie - do any lit bases advance as you get more hits? The video seems to support this.
at 20 seconds, there's a man on third. He hits a double target. The runner on third scores, and the second base lights up. Can't see the backbox, but I assume he scored a run.

Different scenario.
Say you start a game and hit a single. The light for first base should light, and the lights for the '1' targets should go off. What should happen if you hit an unlit '1' target or have the ball go through an inlane at that time? Does that count as a second single, or since the single lights are off, do you get points alone instead? At roughly a minute into the video it appears to be the case that you get another single. He scores a single with the varitarget, first base lights up and the '1' lights go off. The ball goes through the inlane, and 2nd base lights up. Basically, the runner advanced.

It seems to me that the lights near the numbered stand ups really just act as the opposite of the bases. If a base is currently lit, the lights next to the corresponding stand ups are unlit. Lit or unlit, all of the hit switches still seem to score their hits regardless.

The rub:
I noticed a sequence in that video that confuses me a bunch. At about 1:38 the player has a man on first. The '1' lights are off. The others are on.
He hits a triple rollover at the top of the playfield. The runner on first scores (I assume he gets a run), and the third base light turns on. At the same time, the '1' lights re-light, and the '3' lights go out. All as expected.
BUT
In the next few seconds, the ball hits a '2' standup, and then a '1' standup.
In my mind, the '2' would score the runner on third and light second base. The subsequent '1' would move that runner to third and light first base.
1st and 3rd should be lit, with just the '3' stand up lights on.
However, watch the video.
When he hits the '2' followed by the '1' - second base lights up, and then first base lights up. The runner on third never scores. He's left with all three bases lit (And all of the standup lights are off.) Even Bartolo Colon would have scored from third in this scenario.
Please tell me this was just his game acting up, or that those targets were hit too rapidly for the game to operate properly.
Once loaded, the next two hits are singles. The bases remain loaded each time as expected. A subsequent triple clears the bases and leave a man on third.

Okay - this has turned into a long post, but I really think I need to know how things are supposed to operate before trying to troubleshoot my own issues. I did already fix a couple things with my hits relay - two broken wires and had to tighten the bracket holding the coil. My bases now clear at the start of a game, but are certainly not working properly beyond that.

Anyone with a Playball care to go over the rules for me?

Just dawned on me that I've got a ticket for the Tom Taylor collection at MGC next week. Might just be a good chance to answer some of these questions.

Ohhhhhh. Thanks for that stand up target clarification. That makes everything make so much more sense! Including that man already on third - double - single now the bases are loaded thing. That was just baffling me. Man on third doesn't score on a double? HOW???

Thank you SO much.

Back to it then. Sadly, it looks like i have a number of potentially bad lamp sockets, including 1st and 2nd base. All others either work, or are ones that I know should be lit at the start of a game. Going to have to solder them up or wait for a PBR order to arrive. Feels like a recipe for frustration trying to trouble shoot it before I know they're working in the first place.