diff --git a/app/controllers/Tournament.scala b/app/controllers/Tournament.scala
index d5c8a14ff0..1310abee7c 100644
--- a/app/controllers/Tournament.scala
+++ b/app/controllers/Tournament.scala
@@ -2,7 +2,7 @@ package controllers
 
 import lila._
 import views._
-import tournament.{ Created }
+import tournament.{ Created, Started }
 import http.Context
 
 import scalaz.effects._
@@ -21,30 +21,49 @@ object Tournament extends LilaController {
   private def userRepo = env.user.userRepo
 
   val home = Open { implicit ctx ⇒
-    IOk(repo.created map { tournaments ⇒
-      html.tournament.home(tournaments)
-    })
+    IOk(
+      for {
+        createds ← repo.created
+        starteds ← repo.started
+      } yield html.tournament.home(createds, starteds)
+    )
   }
 
   def show(id: String) = Open { implicit ctx ⇒
     IOptionIOk(repo byId id) {
-      case tour: Created ⇒ for {
-        roomHtml ← messenger render tour
-        users ← userRepo byIds tour.data.users
-      } yield html.tournament.show.created(
-        tour = tour,
-        roomHtml = Html(roomHtml),
-        version = version(tour.id),
-        users = users
-      )
-      case _ ⇒ throw new Exception("oups")
+      case tour: Created ⇒ showCreated(tour)
+      case tour: Started ⇒ showStarted(tour)
+      case _             ⇒ throw new Exception("uuuh")
     }
   }
 
+  private def showCreated(tour: Created)(implicit ctx: Context) = for {
+    roomHtml ← messenger render tour
+    users ← userRepo byIds tour.data.users
+  } yield html.tournament.show.created(
+    tour = tour,
+    roomHtml = Html(roomHtml),
+    version = version(tour.id),
+    users = users)
+
+  private def showStarted(tour: Started)(implicit ctx: Context) = for {
+    roomHtml ← messenger render tour
+    users ← userRepo byIds tour.data.users
+  } yield html.tournament.show.started(
+    tour = tour,
+    roomHtml = Html(roomHtml),
+    version = version(tour.id),
+    users = users)
+
   def join(id: String) = Auth { implicit ctx ⇒
     implicit me ⇒
       IOptionIORedirect(repo createdById id) { tour ⇒
-        api.join(tour, me) map { _ ⇒ routes.Tournament.show(tour.id) }
+        api.join(tour, me) map { result ⇒
+          result.fold(
+            err ⇒ { println(err.shows); routes.Tournament.home() },
+            _ ⇒ routes.Tournament.show(tour.id)
+          )
+        }
       }
   }
 
@@ -75,7 +94,10 @@ object Tournament extends LilaController {
         forms.create.bindFromRequest.fold(
           err ⇒ io(BadRequest(html.message.form(err))),
           setup ⇒ api.createTournament(setup, me).map(tournament ⇒
-            Redirect(routes.Tournament.show(tournament.id))
+            tournament.fold(
+              err ⇒ { println(err.shows); Redirect(routes.Tournament.home()) },
+              tour ⇒ Redirect(routes.Tournament.show(tour.id))
+            )
           ))
       }
   }
diff --git a/app/core/Cron.scala b/app/core/Cron.scala
index 286f75a390..809937fc27 100644
--- a/app/core/Cron.scala
+++ b/app/core/Cron.scala
@@ -86,12 +86,12 @@ object Cron {
 
     // also sent when the last player joins
     message(8 seconds) {
-      env.tournament.organizer -> tournament.StartTournament
+      env.tournament.organizer -> tournament.StartTournaments
     }
 
     // also sent when a player completes a game
     message(5 seconds) {
-      env.tournament.organizer -> tournament.StartPairing
+      env.tournament.organizer -> tournament.StartPairings
     }
 
     def message(freq: Duration)(to: (ActorRef, Any)) {
diff --git a/app/package.scala b/app/package.scala
index 0eb828770c..75d60f2799 100644
--- a/app/package.scala
+++ b/app/package.scala
@@ -34,7 +34,7 @@ package object lila
   }
   RegisterJodaTimeConversionHelpers()
 
-  def !![A](msg: String) = msg.failNel[A]
+  def !![A](msg: String): Valid[A] = msg.failNel[A]
 
   def nowMillis: Double = System.currentTimeMillis
   def nowSeconds: Int = (nowMillis / 1000).toInt
diff --git a/app/tournament/Organizer.scala b/app/tournament/Organizer.scala
index ba970da7fc..0509db05b3 100644
--- a/app/tournament/Organizer.scala
+++ b/app/tournament/Organizer.scala
@@ -20,22 +20,24 @@ final class Organizer(
 
   def receive = {
 
-    case StartTournament ⇒ startTournament.unsafePerformIO
+    case StartTournaments               ⇒ startTournaments.unsafePerformIO
+    case StartTournament(tour: Created) ⇒ api.start(tour).unsafePerformIO
 
-    case StartPairing    ⇒ startPairing.unsafePerformIO
+    case StartPairings                  ⇒ startPairings.unsafePerformIO
+    case StartPairing(tour: Started)    ⇒ startPairing(tour).unsafePerformIO
   }
 
-  def startTournament = for {
-    tours ← repo.created
-  } yield (tours filter (_.readyToStart) map api.start).sequence
+  def startTournaments = repo.created flatMap { created =>
+    (created map api.start).sequence
+  } 
 
-  def startPairing = for {
-    tours ← repo.started
-  } yield (for {
-    tour ← tours
-  } yield Pairer(tour).toNel.fold(
-    pairings ⇒ api.makePairings(tour, pairings),
-    io()
-  )).toList.sequence
+  def startPairings = repo.started flatMap { started =>
+    (started map startPairing).sequence
+  }
+  def startPairing(tour: Started) =
+    Pairing.createNewPairings(tour.users, tour.pairings).toNel.fold(
+      pairings ⇒ api.makePairings(tour, pairings),
+      io()
+    )
 
 }
diff --git a/app/tournament/Pairer.scala b/app/tournament/Pairer.scala
deleted file mode 100644
index beb32b09ae..0000000000
--- a/app/tournament/Pairer.scala
+++ /dev/null
@@ -1,14 +0,0 @@
-package lila
-package tournament
-
-object Pairer {
-
-  def apply(tour: Started): List[Pairing] = 
-    tour.pairings.fold(List[Pairing]()) {
-      case (existing, pairings) if existing.status >= chess.Status.Mate =>
-          
-      case _ => pairings
-    }
-
-  private def idlePlayers(pairings: List[Pairings])
-}
diff --git a/app/tournament/Pairing.scala b/app/tournament/Pairing.scala
new file mode 100644
index 0000000000..7bba0e10f0
--- /dev/null
+++ b/app/tournament/Pairing.scala
@@ -0,0 +1,52 @@
+package lila
+package tournament
+
+import game.IdGenerator
+
+case class Pairing(
+    gameId: String,
+    status: chess.Status,
+    user1: String,
+    user2: String) {
+
+  def encode: RawPairing = RawPairing(gameId, status.id, users)
+
+  def users = List(user1, user2)
+  def usersPair = user1 -> user2
+  def contains(user: String) = user1 == user || user2 == user
+
+  def finished = status >= chess.Status.Mate
+  def playing = !finished
+
+  def withStatus(s: chess.Status) = copy(status = s)
+}
+
+case class RawPairing(g: String, s: Int, u: List[String]) {
+
+  def decode: Option[Pairing] = for {
+    status ← chess.Status(s)
+    user1 ← u.lift(0)
+    user2 ← u.lift(1)
+  } yield Pairing(g, status, user1, user2)
+}
+
+object Pairing {
+
+  def apply(user1: String, user2: String): Pairing = new Pairing(
+    gameId = IdGenerator.game,
+    status = chess.Status.Created,
+    user1 = user1,
+    user2 = user2)
+
+  def createNewPairings(users: List[String], pairings: Pairings): Pairings = {
+    val idleUsers: List[String] = pairings.filter(_.playing).foldLeft(users) {
+      (idles, pairing) ⇒ idles filterNot pairing.contains
+    }.toList
+    naivePairing(idleUsers).toList
+  }
+
+  private def naivePairing(users: List[String]) = users grouped 2 collect {
+    case List(u1, u2) ⇒ Pairing(u1, u2)
+  }
+
+}
diff --git a/app/tournament/Tournament.scala b/app/tournament/Tournament.scala
index ea4a2bc0ae..0c628dfcef 100644
--- a/app/tournament/Tournament.scala
+++ b/app/tournament/Tournament.scala
@@ -5,6 +5,7 @@ import org.joda.time.{ DateTime, Duration }
 import org.scala_tools.time.Imports._
 import com.novus.salat.annotations.Key
 import ornicar.scalalib.OrnicarRandom
+import scalaz.NonEmptyList
 
 import user.User
 
@@ -21,16 +22,18 @@ sealed trait Tournament {
   val data: Data
   def encode: RawTournament
 
-  import data._
-
+  def minutes = data.minutes
   lazy val duration = new Duration(minutes * 60 * 1000)
 
-  def missingUsers = minUsers - users.size
-
+  def users = data.users
+  def nbUsers = users.size
+  def minUsers = data.minUsers
   def contains(username: String): Boolean = users contains username
   def contains(user: User): Boolean = contains(user.id)
+  def missingUsers = minUsers - users.size
 
   def showClock = "2 + 0"
+  def createdBy = data.createdBy
 }
 
 case class Created(
@@ -67,32 +70,17 @@ case class Started(
     startedAt: DateTime,
     pairings: List[Pairing]) extends Tournament {
 
+  def addPairings(ps: NonEmptyList[Pairing]) =
+    copy(pairings = pairings ::: ps.list)
+
   def encode = new RawTournament(
     id = id,
-    status = Status.Created.id,
+    status = Status.Started.id,
     data = data,
     startedAt = startedAt.some,
     pairings = pairings map (_.encode))
 }
 
-case class Pairing(
-    gameId: String,
-    status: chess.Status,
-    users: List[String]) {
-
-  def encode: RawPairing = RawPairing(gameId, status.id, users)
-}
-
-case class RawPairing(
-    g: String,
-    s: Int,
-    u: List[String]) {
-
-  def decode: Option[Pairing] = chess.Status(s) map { status ⇒
-    Pairing(g, status, u)
-  }
-}
-
 case class RawTournament(
     @Key("_id") id: String,
     status: Int,
@@ -106,7 +94,7 @@ case class RawTournament(
 
   def started: Option[Started] = for {
     stAt ← startedAt
-    if status == Status.Created.id
+    if status == Status.Started.id
   } yield Started(
     id = id,
     data = data,
@@ -115,7 +103,11 @@ case class RawTournament(
 
   def decodePairings = pairings map (_.decode) flatten
 
-  def any: Option[Tournament] = created
+  def any: Option[Tournament] = Status(status) flatMap {
+    case Status.Created ⇒ created
+    case Status.Started ⇒ started
+    case _              ⇒ None
+  }
 }
 
 object Tournament {
@@ -141,5 +133,5 @@ object Tournament {
 
   val minUsers = (2 to 4) ++ (5 to 30 by 5)
   val minUserDefault = 10
-  val minUserChoices = options(minUsers, "%d players{s}")
+  val minUserChoices = options(minUsers, "%d player{s}")
 }
diff --git a/app/tournament/TournamentApi.scala b/app/tournament/TournamentApi.scala
index e574fa9a10..df8b7461a7 100644
--- a/app/tournament/TournamentApi.scala
+++ b/app/tournament/TournamentApi.scala
@@ -12,28 +12,45 @@ final class TournamentApi(
     repo: TournamentRepo,
     socket: Socket) {
 
-  def makePairings(tour: Started, pairings: NonEmptyList[Pairing]): IO[Unit] = {
-    io()
-  }
+  def makePairings(tour: Started, pairings: NonEmptyList[Pairing]): IO[Unit] =
+    (tour addPairings pairings) |> { tour2 ⇒
+      for {
+        _ ← repo saveIO tour2
+        _ ← (pairings map { pairing ⇒
+          io() // create the game
+        }).sequence
+      } yield ()
+    }
 
-  def createTournament(setup: TournamentSetup, me: User): IO[Created] =
-    Tournament(
-      createdBy = me.id,
-      minutes = setup.minutes,
-      minUsers = setup.minUsers
-    ) |> { created ⇒
-        repo saveIO created map (_ ⇒ created)
-      }
+  def createTournament(setup: TournamentSetup, me: User): IO[Valid[Created]] = for {
+    hasTournament ← repo userHasRunningTournament me.id
+    tournament ← hasTournament.fold(
+      io(alreadyInATournament(me)),
+      Tournament(
+        createdBy = me.id,
+        minutes = setup.minutes,
+        minUsers = setup.minUsers
+      ) |> { created ⇒ repo saveIO created map (_ ⇒ created.success) }
+    )
+  } yield tournament
 
-  def start(created: Created): IO[Unit] = repo saveIO created.start
+  def start(created: Created): IO[Unit] =
+    repo saveIO created.start doIf created.readyToStart
 
-  def join(tour: Created, me: User): IO[Unit] = (tour join me).fold(
-    err ⇒ putStrLn(err.shows),
-    tour2 ⇒ for {
-      _ ← repo saveIO tour2
-      _ ← io(socket reloadUserList tour.id)
-    } yield ()
-  )
+  def join(tour: Created, me: User): IO[Valid[Unit]] = for {
+    hasTournament ← repo userHasRunningTournament me.id
+    tour2Valid = for {
+      tour2 ← tour join me
+      _ ← hasTournament.fold(alreadyInATournament(me), true.success)
+    } yield tour2
+    result ← tour2Valid.fold(
+      err ⇒ io(failure(err)),
+      tour2 ⇒ for {
+        _ ← repo saveIO tour2
+        _ ← io(socket reloadUserList tour.id)
+      } yield ().success
+    ): IO[Valid[Unit]]
+  } yield result
 
   def withdraw(tour: Created, me: User): IO[Unit] = (tour withdraw me).fold(
     err ⇒ putStrLn(err.shows),
@@ -42,4 +59,7 @@ final class TournamentApi(
       _ ← io(socket reloadUserList tour.id)
     } yield ()
   )
+
+  private def alreadyInATournament[A](user: User) = 
+    !![A]("%s already has a tournament in progress" format user.username)
 }
diff --git a/app/tournament/TournamentRepo.scala b/app/tournament/TournamentRepo.scala
index 96ddee6f37..e38e6807d7 100644
--- a/app/tournament/TournamentRepo.scala
+++ b/app/tournament/TournamentRepo.scala
@@ -36,6 +36,12 @@ class TournamentRepo(collection: MongoCollection)
     update(idSelector(tourId), $set("data.users" -> userIds.distinct))
   }
 
+  def userHasRunningTournament(username: String): IO[Boolean] = io {
+    collection.findOne(
+      ("status" $ne Status.Finished.id) ++ ("data.users" -> username)
+    ).isDefined
+  }
+
   def saveIO(tournament: Tournament): IO[Unit] = io {
     save(tournament.encode)
   }
diff --git a/app/tournament/actorApi.scala b/app/tournament/actorApi.scala
index 3be5bd7746..fdfc6a00f6 100644
--- a/app/tournament/actorApi.scala
+++ b/app/tournament/actorApi.scala
@@ -39,5 +39,7 @@ case object HubTimeout
 case object GetNbHubs
 
 // organizer
-case object StartTournament
-case object StartPairing
+case object StartTournaments
+case class StartTournament(tour: Created)
+case object StartPairings
+case class StartPairing(tour: Started)
diff --git a/app/views/tournament/home.scala.html b/app/views/tournament/home.scala.html
index 492c5fd6ab..eec53668e7 100644
--- a/app/views/tournament/home.scala.html
+++ b/app/views/tournament/home.scala.html
@@ -1,4 +1,4 @@
-@(tournaments: List[lila.tournament.Tournament])(implicit ctx: Context)
+@(createds: List[lila.tournament.Created], starteds: List[lila.tournament.Started])(implicit ctx: Context)
 
 @tournament.layout(
 title = "Tournaments") {
@@ -7,9 +7,62 @@ title = "Tournaments") {
 
     <h1 class="lichess_title">Tournaments</h1>
     <div class="body">
-      list of tournaments
+      <table class="createds tournaments">
+        <thead>
+          <tr>
+            <th rowspan="4">Incoming tournaments</th>
+          </tr>
+        </thead>
+        <tbody>
+        @createds.map { tournament =>
+        <tr>
+          <td>
+            <a href="@routes.Tournament.show(tournament.id)">
+              @userIdToUsername(tournament.createdBy)'s tournament
+            </a>
+          </td>
+          <td>@tournament.showClock</td>
+          <td>@tournament.minutes minutes</td>
+          <td>@tournament.nbUsers / @tournament.minUsers players</td>
+          <td>
+            @if(ctx.me.fold(tournament.contains, false)) {
+            JOINED
+            }
+          </td>
+        </tr>
+        }
+        </tbody>
+      </table>
+      <table class="starteds tournaments">
+        <thead>
+          <tr>
+            <th rowspan="4">In progress</th>
+          </tr>
+        </thead>
+        <tbody>
+        @starteds.map { tournament =>
+        <tr>
+          <td>
+            <a href="@routes.Tournament.show(tournament.id)">
+              @userIdToUsername(tournament.createdBy)'s tournament
+            </a>
+          </td>
+          <td>@tournament.showClock</td>
+          <td>@tournament.minutes minutes</td>
+          <td>@tournament.nbUsers / @tournament.minUsers players</td>
+          <td>
+            @if(ctx.me.fold(tournament.contains, false)) {
+            JOINED
+            }
+          </td>
+        </tr>
+        }
+        </tbody>
+      </table>
     </div>
-    <a href="@routes.Tournament.form()" class="action button">Create a new tournament</a>
+    <div>
+    <a href="@routes.Tournament.form()" class="action">Create a new tournament</a>
+  </div>
   </div>
 </div>
 }
diff --git a/app/views/tournament/show/created.scala.html b/app/views/tournament/show/created.scala.html
index 8aefe21950..519a46699d 100644
--- a/app/views/tournament/show/created.scala.html
+++ b/app/views/tournament/show/created.scala.html
@@ -1,8 +1,6 @@
 @(tour: lila.tournament.Created, roomHtml: Html, version: Int, users: List[User])(implicit ctx: Context)
 
-@import tour._
-
-@title = @{ tour.showClock + " tournament" }
+@title = @{ tour.showClock + " tournament pending" }
 
 @tournament.show.layout(
 tour = tour,
@@ -10,11 +8,11 @@ roomHtml = roomHtml,
 version = version,
 title = title) {
 
-<h1>@title pending</h1>
+<h1>@title</h1>
 <div>
-  Waiting for @missingUsers players
+  Waiting for @tour.missingUsers players
 </div>
-<div class="user_list" data-href="@routes.Tournament.userList(id)">
+<div class="user_list" data-href="@routes.Tournament.userList(tour.id)">
   @tournament.userList(users)
 </div>
 
diff --git a/app/views/tournament/show/started.scala.html b/app/views/tournament/show/started.scala.html
new file mode 100644
index 0000000000..265e2e4371
--- /dev/null
+++ b/app/views/tournament/show/started.scala.html
@@ -0,0 +1,23 @@
+@(tour: lila.tournament.Started, roomHtml: Html, version: Int, users: List[User])(implicit ctx: Context)
+
+@title = @{ tour.showClock + " tournament in progress" }
+
+@tournament.show.layout(
+tour = tour,
+roomHtml = roomHtml,
+version = version,
+title = title) {
+
+<h1>@title</h1>
+<div class="user_list" data-href="@routes.Tournament.userList(tour.id)">
+  @tournament.userList(users)
+</div>
+
+@ctx.me.filter(tour.contains).map { me =>
+<div>
+  <form action="@routes.Tournament.withdraw(tour.id)" method="POST">
+    <input type="submit" class="submit button" value="Withdraw" />
+  </form>
+</div>
+}
+}
diff --git a/test/PairingTest.scala b/test/PairingTest.scala
new file mode 100644
index 0000000000..06e0ac9791
--- /dev/null
+++ b/test/PairingTest.scala
@@ -0,0 +1,76 @@
+package lila
+package tournament
+
+import tournament._
+
+class PairingTest extends LilaSpec {
+
+  import Pairing._
+
+  val u1 = "u1"
+  val u2 = "u2"
+  val u3 = "u3"
+  val u4 = "u4"
+  val u5 = "u5"
+
+  "Create new pairings" should {
+    "2 players" in {
+      val users = List(u1, u2)
+      "first pairing" in {
+        val pairings = List[Pairing]()
+        pairs(users, pairings) must_== List(u1 -> u2)
+      }
+      "finished pairing" in {
+        val pairings = List(mate(u1, u2))
+        pairs(users, pairings) must_== List(u1 -> u2)
+      }
+      "started pairing" in {
+        val pairings = List(started(u1, u2))
+        pairs(users, pairings) must_== Nil
+      }
+      "finished and started pairing" in {
+        val pairings = List(mate(u1, u2), started(u1, u2))
+        pairs(users, pairings) must_== Nil
+      }
+    }
+  }
+  "3 players" should {
+    val users = List(u1, u2, u3)
+    "first pairing" in {
+      val pairings = List[Pairing]()
+      pairs(users, pairings) must beOneOf(List(u1 -> u2), List(u1 -> u3), List(u2 -> u3))
+    }
+    "finished pairing" in {
+      val pairings = List(mate(u1, u2))
+      pairs(users, pairings) must_== List(u1 -> u3)
+    }
+    "started pairing" in {
+      val pairings = List(started(u1, u2))
+      pairs(users, pairings) must_== Nil
+    }
+    "finished and started pairing" in {
+      val pairings = List(mate(u1, u2), started(u1, u3))
+      pairs(users, pairings) must_== Nil
+    }
+    "many finished pairings" in {
+      "without ambiguity" in {
+        val pairings = List(mate(u1, u2), mate(u1, u3))
+        pairs(users, pairings) must_== List(u2 -> u3)
+      }
+      "favor longer idle" in {
+        val pairings = List(mate(u1, u2), mate(u1, u3), mate(u2, u3))
+        pairs(users, pairings) must_== List(u1 -> u2)
+      }
+    }
+  }
+
+  private def pairs(users: List[String], pairings: Pairings) =
+    createNewPairings(users, pairings) map (_.usersPair) map {
+      case (a, b) ⇒ (a < b).fold(a -> b, b -> a)
+    }
+
+  private def started(a: String, b: String) =
+    Pairing(a, b) withStatus chess.Status.Started
+  private def mate(a: String, b: String) =
+    Pairing(a, b) withStatus chess.Status.Mate
+}