MLB Immaculate Grid offers users a unique chance. Not only does the exercise help to test one's knowledge of the current state of MLB, but also the history of the sport.
The 3 x 3 quiz game uses a simple format. Users must follow the clues along each axes of the grid array. By doing so, they can estimate the names of MLB players that need to be filled into the blank spaces.
On September 30, Immaculate Grid asked users to name members of the Kansas City Royals to have made the Baseball Hall of Fame.

"Immaculate Grid 181. Retweet or reply with your score!" - Immaculate Grid
Kansas City Royals players in the Baseball Hall of Fame | MLB Immaculate Grid September 30
As the holder of virtually every single-season Kansas City Royals hitting stat, George Brett is nothing short of legendary. The corner infielder spent his entire 21-year career in KC. A member of the exclusive 3,000 hit club, the West Virginia-native won the AL batting title three times, including his MVP 1980 season wherein he slashed .390/.454/.664 with an OPS of 1.118, leading the league in all three categories. Brett was inducted into the Baseball Hall of Fame in 1999.
"Willie Wilson pours champagne on George Brett after the Royals completed the 3-1 comeback against the Blue Jays in the 1985 #ALCS" - Baseball in Pics
As the Washington Senators became Minnesota Twins in 1961, Harmon Killebrew was still the same player as he was before. In 1969, Killebrew hit 49 home runs and 140 RBIs, leading MLB in both categories. In 1975, after twenty years with the Senators/Twins, Killebrew came to the Royals, hitting .14 home runs and 44 RBIs in 106 games before retiring at the end of the season. Killebrew was inducted into the Baseball Hall of Fame in 1984.
"11/10/75. The #Royals release Harmon Killebrew, ending a 22-year career marked by 573 home runs. He joins other long-time Royals Gaylord Perry and Orlando Cepeda in the Hall of Fame." - J. Daniel
In 1958, Puerto Rican first baseman Orlando Cepeda hit 312/.342/.512 with the San Francisco Giants to win the NL Rookie of the Year Award. In 1966, Cepeda was traded to the Cardinals, where he hit .325 with 25 home runs and an MLB-best 11 RBIs in 1967 to win the NL MVP Award. In 1974, Cepeda played 33 games with the Royals before announcing his retirement. Now an 86 year old, Cepeda's name was enshrined at Coopestown in 1999, the same year as George Brett.