diff --git a/conn_stats.go b/conn_stats.go
index a54fd7b8..144ab0cb 100644
--- a/conn_stats.go
+++ b/conn_stats.go
@@ -36,6 +36,7 @@ type ConnStats struct {
 }
 
 func (cs *ConnStats) wroteMsg(msg *pp.Message) {
+	// TODO: Track messages and not just chunks.
 	switch msg.Type {
 	case pp.Piece:
 		cs.ChunksWritten++
diff --git a/connection.go b/connection.go
index 7e475659..3824fc3d 100644
--- a/connection.go
+++ b/connection.go
@@ -210,6 +210,7 @@ func (cn *connection) WriteStatus(w io.Writer, t *Torrent) {
 		cn.completedString(),
 		len(cn.peerTouchedPieces),
 		cn.stats.ChunksReadUseful,
+		// TODO: Use ChunksRead? Verify that value is the same as this sum?
 		cn.stats.ChunksReadUnwanted+cn.stats.ChunksReadUseful,
 		cn.stats.ChunksWritten,
 		cn.numLocalRequests(),
diff --git a/peer_protocol/decoder.go b/peer_protocol/decoder.go
index 2d82c1c6..3f66cdc9 100644
--- a/peer_protocol/decoder.go
+++ b/peer_protocol/decoder.go
@@ -17,6 +17,7 @@ type Decoder struct {
 }
 
 // io.EOF is returned if the source terminates cleanly on a message boundary.
+// TODO: Is that before or after the message?
 func (d *Decoder) Decode(msg *Message) (err error) {
 	var length Integer
 	err = binary.Read(d.R, binary.BigEndian, &length)
diff --git a/torrent.go b/torrent.go
index fca91798..a23029bc 100644
--- a/torrent.go
+++ b/torrent.go
@@ -134,6 +134,7 @@ type Torrent struct {
 	// Torrent-level statistics.
 	stats TorrentStats
 
+	// Count of each request across active connections.
 	pendingRequests map[request]int
 }
 
@@ -848,6 +849,8 @@ func (t *Torrent) worstBadConn() *connection {
 		if c.stats.ChunksReadUnwanted >= 6 && c.stats.ChunksReadUnwanted > c.stats.ChunksReadUseful {
 			return c
 		}
+		// If the connection is in the worst half of the established
+		// connection quota and is older than a minute.
 		if wcs.Len() >= (t.maxEstablishedConns+1)/2 {
 			// Give connections 1 minute to prove themselves.
 			if time.Since(c.completedHandshake) > time.Minute {