Vn96.1 Tic Tac Toe 9/19/77
After the final arithmetic session of this date, Miriam wanted to play some tic-tac-toe. (Her purpose was to get the material over with so she could have a friend come play with her on the morrow; her assumption that such was necessary was an error.) These games began with a discussion of Miriam’s play with Glenn Iba (cf. vignette 86).
Bob | I remember a funny thing happened the last time we were at Logo. |
Miriam | What? |
Bob | We were there and you ended up playing tic-tac-toe with Glenn. |
Miriam | Yeah. |
Bob | Was he surprised when you beat him that time? |
Miriam | Yeah. |
Bob | What did he say to you? Did he say, “How did that happen?” |
Miriam | I told him how I was going to beat him in the first time and he spoiled it. |
Bob | In the very first game? |
Miriam | I went here [a corner response]. |
Bob | Yeah. You had a corner opening. |
Miriam | And he went here [center]. I went here [opposite corner], and said if you go here [adjacent corner], I’ll go here and get two ways to win. And he went here [side move] and I had to go here [forced move]. |
Bob | He spoiled your game. |
Miriam | Yeah. |
Bob | That’s why you didn’t beat him in the first game. Do you remember that other game you did beat him in though?… |
Miriam | [no response] |
After Miriam selects a pen (by applying the chant “Engine, engine number 9, going down Chicago line. . .”), we try to discuss the possible responses to Miriam’s opening corner move. Miriam shows no inclination to reduce her count of possible responses based on symmetry arguments.
Game 1: Miriam moves first (letters)
A | 1 | B1->D 2 | C | B | | 3
Miriam’s initial counter-move (B1) to my opening response was not optimal (for a game of the form classed as Game VII in Learning: Tic-tac-toe ). Together we worked through the recorded game above.
Bob | Let’s see if you can beat me when I move right close here to you. Do you know whether you can beat me or not? |
Miriam | Unh-uh. Rats. This red pen [moves on opposite side of my markers]. |
Bob | That’s where you want to go? Miriam, I’m really surprised. Why do you want to go there? |
Miriam | ‘Cause then if I go here [opposite adjacent corner], I can beat you. |
Bob | Now hold on. You’re trying to move there. So then you’ll get two ways to win? … Let me show you’ve got a bug. Miriam, I get to go next, and I’m planning on going there [center]. |
Miriam | Go here. |
Bob | Oh no. The good trick to beat me there is you have to force me to go someplace else. |
Miriam | How? |
Bob | Like, if you crossed out that move and moved in a different corner, like down there. |
Miriam | Yeah? |
Bob | Would it work then? |
Miriam | Maybe. Would it? |
Bob | What do you think? You force me to move over there. Then the center will be free. You think that’ll make it? O. K. Go ahead. |
Miriam | I did. |
Bob | Great. Well, Miriam, I am forced to move here, in the side place. . . . Your chance to win do what? |
Miriam | Come together, this way and this way [moves C]. |
Bob | I will go down there with my 3 then. |
Miriam | I will make this. I win, I win. |
Bob | Why don’t you put a big M over the top for Miriam. . . . But if you fail to force my move, the next time around, my number 2 — I could have put my number 2 right in the middle and that would have screwed your strategy all up. |
Games 2 and 3:
After a replaying of the game situation in which Glenn beat Miriam (cf. vignette 86) — at her request — in which I beat her (the opening game, of form X, is determinate), Miriam spontaneously turns the tables on me in game 3.
numbers first letters first A | | 2 1 | | B C | 3 | 1 3 | C | A 4 | | B D | | 2
Bob | I remember when you were playing with Glenn, you did a lot of playing on the side. He started on the side a lot. Is that because you told him to every time? Or just because he wanted to after the first time? |
Miriam | Will you go over here [the far side from upper left corner]. |
Bob | Over here? What were you going to do? |
Miriam | Here [upper left corner move]. |
Bob | Who do you think will win? |
Miriam | Me? |
Bob | Let’s see. Ah. You’re the letters, I’m the numbers. |
Miriam | Unh-uh. |
Bob | Now you think you’re going to beat me by going up in the corner? |
Miriam | [moves A] |
Bob | That’s a bug, Miriam. Shall I show you why? . . . Do you think you’re going to win, or do you think I’m going to win? |
Miriam | I think you’re going to win. |
Bob | How come? |
Miriam | You just told me. |
Bob | You want to see how I do it? |
Miriam | Yeah. |
Bob | I put my 2 right up here, over top of the 1. Now you have a forced move…. My good trick is that your second move (B) comes right under my 1. Now, tell me, what I’ve got [3 in center square], where my chances to win intersect. |
Miriam | Two ways to win. |
Bob | How did I do that to you? . . . |
Miriam | I’m going to go here. |
Bob | So you block my 1 – 3 and I go there. O. K. One for Bob. . . . Where do you want to start? |
Miriam | [moves A where my 1 had been in last frame] |
Bob | You’re going to go where I went last time? |
Miriam | Yeah. |
Bob | Oh. . . . Is this “turning the tables”? |
Miriam | [laughing] Yeah. |
Bob | Well, that means I have to go up where you went last time, right? |
Miriam | Yeah. |
Bob | O. K. So you’re turning the tables on me. You’re going to be able to beat me now? . . . |
Miriam | Yeah. |
Bob | I will put my 2 down here. |
Miriam | Here? [i. e. is move C in right location?] |
Bob | Uh-huh. |
Miriam | C. |
Bob | Oh. You put it there because you’ve got one chance from the B through the center and one chance from the A across. |
Miriam | [unclear comment] |
Bob | Well, I’ll go here. 3. So you turned the tables on me all right. You like turning the tables on me? Is that a good way to do tic-tac-toe? |
Miriam | Yeah. |
Bob | Here. I go first again? Shall we do another side one? |
Miriam | Let’s stop. I’ll do some more after a while. |
We leave tic-tac-toe for a game of frisbee in the courtyard and do not return to it.
Relevance
Miriam’s play in game 1 shows the residual dominance of the three-corner configuration and an imperfect integration of the idea of a forcing chain (we have not explicitly discussed this idea). Miriam requests we replay the game in which she was defeated in vignette 86, the re-executes it of her own volition in ‘table-turning’ mode. I cite this event as evidence that Miriam has adopted this procedure as a powerful learning tool.