<h2>Hint:</h2>
<p>A player with perfect recall means the player remembers the history of the moves up to the current information set. In particular, he remembers the previous actions he has taken.</p>
<p>Now in Player <span class="math-container">$\mathrm I$</span>'s second information set, can he recall whether he has taken <span class="math-container">$T_1$</span> or <span class="math-container">$B_1$</span> in his first information set?</p>

CC BY-SA 4.0
2020-07-09T17:58:10.097Z
2020-07-09T17:58:10.097Z
Herr K.
<p><a href="https://i.sstatic.net/NfM1J.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/NfM1J.png" alt="enter image description here" /></a></p>
<p>Could someone help guide me on finding the players with perfect recall, and those without?
For those players that do not have perfect recall, what do they forget? Step-by-step guidance would be greatly appreciated!</p>
<p>I am new to game theory and am preparing for a test by solving practice questions in my textbook.</p>
<p>Furthermore, if anyone happens to know of a good resource for working solutions to masters-level game theory problems like these, it would be greatly appreciated! I am still trying to understand how to approach these problems in general.</p>

CC BY-SA 4.0
2020-07-07T11:04:21.050Z
There are two ways to get from the root to I's second information set, $T_1, b$ and $B_1$. Within this information set, I cannot distinguish between the two histories. What does this tell you about I?
VARulle
CC BY-SA 4.0
2020-07-19T14:55:31.357Z
@Tomcat: No, $T_1$ and $B_1,T_2$ are the two ways to reach II's unique information set. The interesting part is in reaching player I's second information set.
VARulle
<game-theory><repeated-games><extensive-games>
Could someone help guide me on finding the players with perfect recall, and those without?
Mark
# Could someone help guide me on finding the players with perfect recall, and those without?

(Asked by: username_0 on 2020-07-07)

[![enter image description here](https://i.sstatic.net/NfM1J.png)](https://i.sstatic.net/NfM1J.png)

Could someone help guide me on finding the players with perfect recall, and those without?
For those players that do not have perfect recall, what do they forget? Step-by-step guidance would be greatly appreciated!

I am new to game theory and am preparing for a test by solving practice questions in my textbook.

Furthermore, if anyone happens to know of a good resource for working solutions to masters-level game theory problems like these, it would be greatly appreciated! I am still trying to understand how to approach these problems in general.

**Tags:** game-theory, repeated-games, extensive-games

> **Comments:**
> **username_1**: There are two ways to get from the root to I's second information set, $T_1, b$ and $B_1$. Within this information set, I cannot distinguish between the two histories. What does this tell you about I?  
> **username_1**: @Tomcat: No, $T_1$ and $B_1,T_2$ are the two ways to reach II's unique information set. The interesting part is in reaching player I's second information set.  

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## 1 answers

### Answer by username_2 on 2020-07-09. Score: 1

## Hint:

A player with perfect recall means the player remembers the history of the moves up to the current information set. In particular, he remembers the previous actions he has taken.

Now in Player $\mathrm I$'s second information set, can he recall whether he has taken $T\_1$ or $B\_1$ in his first information set?


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