diff --git a/game/ai.go b/game/ai.go
index 60018a0..f2b2096 100644
--- a/game/ai.go
+++ b/game/ai.go
@@ -2,7 +2,7 @@ package game
 
 func chooseCommand(s State, teamID int) command {
 	t := s.Teams[teamID]
-	h := t.BatonHolder()
+	h := ActiveBot(t)
 	if collide(h.Position.Pos+1, h.Position.Lane, s) != nil {
 		if h.Position.Lane <= t.Lane && h.Position.Lane < NumLanes-1 {
 			return left
diff --git a/game/commands.go b/game/commands.go
index 19b0ca5..652bd8b 100644
--- a/game/commands.go
+++ b/game/commands.go
@@ -31,6 +31,6 @@ func doCommand(cmd command, s State, teamID int) State {
 		b.Position.Lane--
 	}
 
-	s = updateBot(s, teamID, *b)
+	s = updateBot(s, *b)
 	return s
 }
diff --git a/game/game.go b/game/game.go
index d177e03..aa91b87 100644
--- a/game/game.go
+++ b/game/game.go
@@ -6,7 +6,7 @@ func UpdateState(s State, sOld State) State {
 	for i := range s.Teams {
 		s = doCommand(chooseCommand(s, i), s, i)
 		if b := ActiveBot(s.Teams[i]); b != nil {
-			s = moveBot(s, i, *b)
+			s = moveBot(s, *b)
 		}
 		s = maybePassBaton(s, i)
 	}
@@ -35,12 +35,12 @@ func maybePassBaton(s State, teamID int) State {
 		if abs(b.Position.Pos-h.Position.Pos) <= passDistance {
 			h.v = 0
 			h.a = 0
-			s = updateBot(s, teamID, *h)
+			s = updateBot(s, *h)
 			newH := t.Bots[i]
 			newH.a = baseAccel
 			t.Baton.HolderID = newH.ID
 			s = updateTeam(s, t)
-			return updateBot(s, teamID, newH)
+			return updateBot(s, newH)
 		}
 	}
 
@@ -56,8 +56,8 @@ func ActiveBot(t Team) *Bot {
 	return nil
 }
 
-func updateBot(s State, teamID int, b Bot) State {
-	t := s.Teams[teamID]
+func updateBot(s State, b Bot) State {
+	t := s.Teams[b.TeamID]
 	for i, bb := range t.Bots {
 		if bb.ID == b.ID {
 			bots := append([]Bot{}, t.Bots[:i]...)
@@ -81,6 +81,18 @@ func updateTeam(s State, t Team) State {
 	return s
 }
 
+func destroyBot(s State, b Bot) State {
+	// insert obstacle where bot was
+	s.Obstacles = append(s.Obstacles, Obstacle{Position: b.Position})
+	log.Printf("spawn obstacle at %v", b.Position)
+
+	// spawn bot back at starting position
+	b.Position = b.StartPos
+	log.Printf("respawn bot %d at %v", b.ID, b.Position)
+
+	return updateBot(s, b)
+}
+
 func won(b Bot, s State) bool {
 	return b.Position.Pos >= Steps
 }
@@ -115,18 +127,11 @@ type Team struct {
 	Lane  int
 }
 
-func (t Team) BatonHolder() *Bot {
-	for _, b := range t.Bots {
-		if b.ID == t.Baton.HolderID {
-			return &b
-		}
-	}
-	return nil
-}
-
 type Bot struct {
 	ID       int
+	TeamID   int
 	Position Position
+	StartPos Position
 	v        int
 	a        int
 }
@@ -136,6 +141,11 @@ type Position struct {
 	Pos  int
 }
 
+type Battery struct {
+	Capacity int
+	Charge   int
+}
+
 type Baton struct {
 	HolderID int
 }
@@ -150,12 +160,14 @@ func NewState() State {
 		var bots []Bot
 		for j := 0; j < numBots; j++ {
 			b := Bot{
-				ID: i*NumTeams + j,
-				Position: Position{
+				ID:     i*NumTeams + j,
+				TeamID: i,
+				StartPos: Position{
 					Lane: i,
 					Pos:  j * (Steps / numBots),
 				},
 			}
+			b.Position = b.StartPos
 			bots = append(bots, b)
 		}
 		teams = append(teams, Team{
@@ -199,7 +211,7 @@ func NewState() State {
 
 const (
 	Steps    = 40
-	numBots  = 5
+	numBots  = 4
 	NumTeams = 4
-	NumLanes = 4
+	NumLanes = NumTeams
 )
diff --git a/game/physics.go b/game/physics.go
index ed930d3..d0991dc 100644
--- a/game/physics.go
+++ b/game/physics.go
@@ -21,17 +21,17 @@ func accelerate(b Bot) Bot {
 	return b
 }
 
-func moveBot(s State, teamID int, b Bot) State {
+func moveBot(s State, b Bot) State {
 	for i := 0; i < b.v; i++ {
 		if o := collide(b.Position.Pos+1, b.Position.Lane, s); o != nil {
 			log.Printf("bot %d crashed into %#v!", b.ID, o)
-			break
+			return destroyBot(s, b)
 		} else {
 			b.Position.Pos++
 		}
 	}
 
-	s = updateBot(s, teamID, b)
+	s = updateBot(s, b)
 	return s
 }