Markov Chains
Transition Matrices, Stationary Distributions, and the Memoryless Property — A TLDR Primer
Markov chains show up on probability exams, in college-level discrete math and linear algebra courses, and in real-world topics from Google's PageRank to genetics — yet most textbooks bury the core ideas under pages of theory before you ever see a worked example. This guide cuts straight to what you need.
**TLDR: Markov Chains** covers finite, discrete-time Markov chains from the ground up. You will learn what a Markov chain is and why the memoryless property matters, how to build and read a transition matrix and its diagram, how to compute multi-step probabilities using matrix powers, how to classify states as transient, recurrent, or absorbing, and how to find the stationary distribution by solving a simple system of equations. Every concept arrives with a concrete example before the abstraction.
This is a markov chains explained for beginners guide written for high school students in pre-calculus, statistics, or discrete math, as well as college freshmen and sophomores meeting probability theory for the first time. Parents helping with homework and tutors prepping a session will find it equally useful. The writing is direct and concise — no filler, no padded review sections, no hand-waving past the hard parts.
If you have a probability exam or a class assignment on stochastic processes and you need to get oriented fast, this is the place to start. Grab your copy and go.
- Define a Markov chain and state the memoryless (Markov) property in plain language
- Build a transition matrix from a word problem and interpret its entries
- Compute n-step transition probabilities using matrix powers
- Classify states as transient, recurrent, absorbing, and periodic
- Find a stationary distribution by solving πP = π
- Recognize when a chain converges to its stationary distribution and apply this to real examples
- 1. What Is a Markov Chain?Introduces states, transitions, and the memoryless property using a weather example.
- 2. Transition Matrices and DiagramsShows how to encode a chain as a stochastic matrix and as a directed graph, and how to read each.
- 3. Multi-Step Probabilities and Matrix PowersComputes the probability of being in state j after n steps using P^n and the Chapman-Kolmogorov idea.
- 4. Classifying States: Transient, Recurrent, AbsorbingDistinguishes types of states and shows how absorbing chains model gambler's ruin and similar problems.
- 5. Stationary Distributions and Long-Run BehaviorDefines the stationary distribution, solves πP = π by hand, and states when chains converge to it.
- 6. Where Markov Chains Show UpBriefly tours PageRank, genetics, board games, and queueing to show why the math matters.