Typically, when setting starting lineups, fantasy football owners are looking for players who consistently give them quality games.
However, every year there are players that owners never know what to expect from them on a weekly basis. These players can have weeks when they go over 30 points in a game and then come back the next week to score three.
These six players are must-starts on most fantasy teams, but they can be studs or duds on any given week.
All point totals based on ESPN standard scoring.
Currently the third-highest scoring fantasy running back, Ridley has been a pleasant surprise to fantasy owners this season.
Of his 100 total fantasy points, 79 have come in only four games.
In the other four games he has played in he has averaged only 5.25 points per game, and that is boosted by a nine-point game in Week 2.
His season high came in a Week 5 victory against a terrible Buffalo defense, giving up a league-high 176.9 rushing yards this season, in which he had 106 rushing yards for two touchdowns and 22 fantasy points.
Ridley followed that up with 19 points against Denver, but then had two straight below average games, at Seattle (three points) and against the Jets (six).
In every game that the Patriots' top RB has scored a touchdown, he has topped 100 yards, and every time he has not reached the century mark, he has not scored a TD. That is a classic recipe for a bang or bust player.
So far the No. 3 overall pick in this year's draft has not disappointed the fans in Cleveland.
Trent Richardson is averaging 11.9 fantasy points per game and is the seventh highest scorer at RB this season. But that does not mean he has not had his fair share of ups and downs in his rookie season.
Despite having only two games of 100 yards rushing, Richardson has still managed to score over 15 points in half of his games.
His season high was a 25-point performance at Cincinnati when he had 145 total yards (109 rushing, 36 receiving) and two total touchdowns (one rushing, one receiving).
However, Richardson has also been shut down for three points or less in three of the games this season.
A week ago at Indianapolis, Richardson had a season-low eight carries for only eight yards, resulting in only one fantasy point.
The running back of the future for the Browns has yet to gain 50 or more rushing yards in consecutive games, but had four game touchdown streak in Weeks 2 through 5.
After scoring 34 points and rushing for 233 yards in Week 3, it seemed the pre-torn ACL version of Jamaal Charles was back.
He proved it was not a fluke with two promising games, posting totals of 18 and 16 fantasy points.
After those three games, Charles fell into a funk, having only 40 rushing yards in Week 6. He followed that with an embarrassing game after a bye week with only five carries for four yards and zero fantasy points.
Charles has been one of the toughest fantasy backs to figure out, as he has only scored two TDs this season and has only gone over 100 yards twice, as well.
On a team that is always losing, it is tough for the Chiefs to keep on giving the ball to Charles, and the problem is compounded with a terrible passing game.
He still is Jamaal Charles and he can go off for huge games at any time, so people will continue start him.
Yes, the current leader (tied with AJ Green) in fantasy points among wide receivers is on my list of biggest bang or bust fantasy players.
His season low two points against Dallas in week eight was a big reason he is a part of this group of players. That week joins weeks one (also against Dallas) and three as Cruz's "bust" weeks.
Aside from those games he has four games with 16 or more points, and another game with 11.
His high fantasy score this season is 23 points, which he has hit twice, the first against Tampa Bay with 11 receptions, 179 yards and a touchdown. The second came against the Cleveland Browns in which he only totaled 50 yards, but reached the end zone on three of his five catches.
There is not a single fantasy owner out there that I would suggest not to start Cruz, but be aware that he has only had three 100 yard receiving games this season, and any game he has not scored a touchdown he has scored five fantasy points or less.
With 89 total fantasy points on the season, Vincent Jackson currently has the fourth most points among receivers.
However Jackson has disappeared in just about as many games as he has gone off in.
In his seven games, four of them have resulted in 16 or more points (19.75 points per game), while his other three games he has gotten four or less (3.33).
He has a high of 27 in a Week 7 matchup against New Orleans when he had seven catches for an unbelievable 216 yards and a touchdown. He followed that with an unspectacular game against the Vikings with two grabs for 40 yards. TB scored 36 points as a team that game.
Jackson's potential to go off every week has made him a must-start, despite never having more than 70 yards receiving in consecutive weeks this season.
Marques Colston, the sixth highest scoring wideout in the league, has had most of his scoring come in the span of three weeks.
After being a below-average fantasy receiver for the first three weeks of the season, scoring five, four, and four points in those games, Colston finally went off in Week 4.
Against the Green Bay Packers, the former seventh-round pick finally showed what he was capable of with nine grabs for 153 yards and a touchdown.
He followed with an even better performance against San Diego on Sunday Night Football. Again totaling nine catches, he had 131 yards and found the end zone three times for 31 fantasy points. He led the entire league in fantasy points that week.
However, with so many weapons on the Saints' offense, Colston has a lot of competition for catches. In games when he has over five catches, he has averaged 21.67 fantasy points per game, and when he has gotten fewer, he has only averaged 4.75 points.